KR20100125144A - Apparatus for magnetic anisotropy constant measurement - Google Patents

Abstract

PURPOSE: A device for measuring a magnetic anisotropy constant is provided to stably measure the magnetic anisotropy constant of a magnetic element by measuring an electric signal like the electric resistance or hall voltage of the magnetic element. CONSTITUTION: A magnetic field generator(100) applies a uniform magnetic field and forms a magnetic space. A rotating unit(200) rotates a magnetic element around a fixed axis. A data measuring unit(300) measures the resistance of a magnetic element. An operator(400) operates the magnetic anisotropy constant of the magnetic element.

Description

Magnetic anisotropy constant measuring device {APPARATUS FOR MAGNETIC ANISOTROPY CONSTANT MEASUREMENT}

The present invention relates to a magnetic anisotropy constant measuring apparatus and measuring method. More specifically, the present invention relates to an apparatus and a method for measuring the magnetic anisotropy constant of a magnetic body by measuring electrical resistance or hall voltage.

The magnetic anisotropy constant of a magnetic body is a value representing the basic properties of the magnetic body and is important data for determining the characteristics of the magnetic body. Torque magnetometer is a device for measuring the magnetic anisotropy constant. The torque magnetometer calculates the magnetic anisotropy constant of the material by applying an external magnetic field to the sample to be measured and measuring the force generated by the magnetization state of the sample. However, when the size of the sample to be measured is reduced, the magnitude of the force to be measured is also reduced, so that the measurement of the magnetic anisotropy constant may be impossible. Considering the fact that the recent development of science and technology is very small and ultra-precision, the limitation of the torque magnetometer is revealed. In addition, the torque magnetometer has a disadvantage in that it is vulnerable to physical problems such as external vibration and friction because it measures precise force.

An object of the present invention is to provide a magnetic anisotropy constant measuring apparatus and method capable of stably measuring the magnetic anisotropy constant of a magnetic material having a micro or nanometer size.

)에 따라 자성체의 저항값(R)을 측정하는 데이터측정부, 및 측정된 외부자기장의 각도(

)에 따른 저항값(R)을 이용하여 자성체의 자기이방성상수(K)를 연산하는 자기이방성상수 연산부를 포함한다.Magnetic anisotropy constant measuring device according to the present invention, a magnetic field generating unit for forming a magnetic space by applying a uniform magnetic field, a rotating unit for rotating the magnetic body around a certain axis in the magnetic space, the magnetic axis for magnetization and the magnetic body is applied to The angle of the external magnetic field, which is the angle made by the direction of the magnetic field,

Data measuring unit for measuring the resistance value (R) of the magnetic body according to the, and the measured angle of the external magnetic field (

It includes a magnetic anisotropy constant calculating unit for calculating the magnetic anisotropy constant (K) of the magnetic material using the resistance value R according to).

Data measurement unit,

)에 따라 자성체의 전압값을 측정하는 전압측정부, 및 측정된 외부자기장의 각도(

)에 따른 전압값을, 외부자기장의 각도(

)에 따른 저항값(R)으로 변환하는 데이터변환부를 포함하는 것이 바람직하다.It is connected to the electrodes of both ends of the magnetic material, the current supply unit for supplying a constant current to the magnetic material through the electrodes of the both ends of the magnetic material, the electrode of the both ends of the magnetic material, and measure the voltage value of the magnetic material through the electrodes of both ends of the magnetic material, Angle of external magnetic field (

The voltage measuring unit for measuring the voltage value of the magnetic body according to, and the measured angle of the external magnetic field (

The voltage value according to) is the angle of the external magnetic field (

It is preferable to include a data conversion unit for converting into a resistance value (R) according to.

Magnetic anisotropy constant calculating unit,

)에 따른 저항값(R)을 이용하여, 측정된 저항값(R)과 외부자기장의 각도(

)의 함수를, 자성체의 자화용이축과 자화방향이 이루는 각도인 자화각도(θ)와 외부자기장의 각도(

)의 함수로 변환하고, Measured external magnetic field angle (

Using the resistance value R according to), the measured resistance value R and the angle of the external magnetic field (

The function of) is the angle of magnetization (θ), which is the angle between the easy axis of magnetization and the magnetization direction, and the angle of the external magnetic field (

To a function of),

)의 함수를, 이론식Magnetization angle (θ) and angle of external magnetic field (

) Function,

Calculate the magnetic anisotropy (K) of the magnetic material by applying to

H is the strength of the magnetic field applied to the magnetic material, M is preferably the saturation magnetization constant of the magnetic material.

)에 따라 자성체의 홀 전압값(V_H)을 측정하는 데이터측정부, 및 측정된 외부자기장의 각도(

)에 따른 홀 전압값(V_H)을 이용하여 자성체의 자기이방성상수(K)를 연산하는 자기이방성상수 연산부를 포함한다.Magnetic anisotropy constant measuring device according to the present invention, a magnetic field generating unit for forming a magnetic space by applying a uniform magnetic field, a rotating unit for rotating the magnetic body around a certain axis in the magnetic space, the magnetic axis for magnetization and the magnetic body is applied to The angle of the external magnetic field, which is the angle made by the direction of the magnetic field,

Data measuring unit for measuring the Hall voltage value (V _H ) of the magnetic material according to the, and the angle of the measured external magnetic field (

A magnetic anisotropy constant calculating unit for calculating the magnetic anisotropy constant (K) of the magnetic material by using the Hall voltage value (V _H ) according to).

Data measurement unit,

)에 따라 자성체의 홀 전압값(V_H)을측정하는 전압측정부를 포함하는 것이 바람직하다.A current supply unit connected to the electrodes of the first both ends of the magnetic body and supplying a constant current to the magnetic body through the electrodes of the first both ends, and the electrodes of the second both ends in a position perpendicular to the electrodes of the first both ends of the magnetic body; Is measured, and the Hall voltage value (V _H ) of the magnetic body is measured through the electrodes at both ends, and the angle of the external magnetic field (

It is preferable to include a voltage measuring unit for measuring the Hall voltage value (V _H ) of the magnetic material according to).

Magnetic anisotropy constant calculating unit,

)에 따른 홀 전압값을 이용하여, 측정된 홀전압(V_H)과 외부자기장의 각도(

)의 함수를, 자성체의 자화용이축과 자화방향이 이루는 각도인 자화각도(θ)와 외부자기장의 각도(

)의 함수로 변환하고, Measured external magnetic field angle (

Using the Hall voltage value according to), the measured Hall voltage (V _H ) and the angle of the external magnetic field (

The function of) is the angle of magnetization (θ), which is the angle between the easy axis of magnetization and the magnetization direction, and the angle of the external magnetic field (

To a function of),

)의 함수를, 이론식Magnetization angle (θ) and angle of external magnetic field (

) Function,

Calculate the magnetic anisotropy (K) of the magnetic material by applying to

H is the strength of the magnetic field applied to the magnetic material, M is preferably the saturation magnetization constant of the magnetic material.

)에 따라 자성체의 저항값(R)을 측정하는 데이터측정단계, 및 측정된 외부자기장의 각도(

)에 따른 저항값(R)을 이용하여 자성체의 자기이방성상수(K)를 연산하는 자기이방성상수 연산단계를 포함한다.Magnetic anisotropy constant measuring method according to the present invention, a magnetic field applying step to form a magnetic space by applying a uniform magnetic field, a rotating step of rotating the magnetic body around a certain axis in the magnetic space, the magnetic axis for magnetization and applied to the magnetic body The angle of the external magnetic field, which is the angle formed by the direction of the magnetic field

Data measurement step of measuring the resistance value (R) of the magnetic material according to the, and the measured angle of the external magnetic field (

Magnetic anisotropy constant calculation step of calculating the magnetic anisotropy constant (K) of the magnetic material by using the resistance value (R) according to).

Data measurement step,

)에 따라 자성체의 전압값을 측정하는 전압측정단계, 및 측정된 외부자기장의 각도(

)에 따른 전압값을 외부자기장의 각도(

)에 따른 저항값(R)으로 변환하는 데이터변환단계를 포함하는 것이 바람직하다.The current supply step of supplying a constant current to the magnetic material through the electrodes on both ends of the magnetic material, by measuring the voltage of the magnetic material through the electrodes on both ends of the magnetic material, the angle of the external magnetic field (

The voltage measuring step of measuring the voltage value of the magnetic material according to, and the measured angle of the external magnetic field (

Voltage value according to)

It is preferable to include a data conversion step of converting the resistance value (R) according to.

Magnetic anisotropy constant calculation step,

)에 따른 저항값(R)을 이용하여, 측정된 저항값(R)과 외부자기장의 각도(

)의 함수를, 자성체의 자화용이축과 자화방향이 이루는 각도인 자화각도(θ)와 외부자기장의 각도(

)의 함수로 변환하는 변환단계와,Measured external magnetic field angle (

Using the resistance value R according to), the measured resistance value R and the angle of the external magnetic field (

The function of) is the angle of magnetization (θ), which is the angle between the easy axis of magnetization and the magnetization direction, and the angle of the external magnetic field (

A conversion step of converting the

)의 함수를, 이론식Magnetization angle (θ) and angle of external magnetic field (

) Function,

Computing the magnetic anisotropy constant (K) of the magnetic material by applying to,

H is the strength of the magnetic field applied to the magnetic material, M is preferably the saturation magnetization constant of the magnetic material.

)에 따라 자성체의 홀 전압값(V_H)을 측정하는 데이터측정단계, 및 측정된 외부자기장의 각도(

)에 따른 홀 전압값(V_H)을 이용하여 자성체의 자기이방성상수(K)를 연산하는 자기이방성상수 연산단계를 포함한다.Magnetic anisotropy constant measuring method according to the present invention, a magnetic field applying step of forming a magnetic space by applying a uniform magnetic field, a rotating step of rotating the magnetic body about a certain axis in the magnetic space, the magnetic axis for magnetization and applied to the magnetic body The angle of the external magnetic field, which is the angle formed by the direction of the magnetic field,

The data measuring step of measuring the Hall voltage value (V _H ) of the magnetic material according to, and the angle of the measured external magnetic field (

Magnetic anisotropy constant calculation step of calculating the magnetic anisotropy constant (K) of the magnetic material using the Hall voltage value (V _H ) according to).

Data measurement step,

)에 따라 자성체의 홀 전압값(V_H)을측정하는 전압측정단계를 포함하는 것이 바람직하다.A current supplying step of supplying a constant current to the magnetic material through the electrodes at the first both ends of the magnetic material, and the Hall voltage value of the magnetic material through the electrodes at both ends perpendicular to the electrodes of the first both ends of the magnetic material ( V _H ), but the angle of the external magnetic field (

It is preferable to include a voltage measuring step of measuring the Hall voltage value (V _H ) of the magnetic material according to).

Magnetic anisotropy constant calculation step,

)에 따른 홀 전압값을 이용하여, 측정된 홀전압(V_H)과 외부자기장의 각도(

)의 함수를, 자성체의 자화용이축과 자화방향이 이루는 각도인 자화각도(θ)와 외부자기장의 각도(

)의 함수로 변환하는 변환단계와,Measured external magnetic field angle (

Using the Hall voltage value according to), the measured Hall voltage (V _H ) and the angle of the external magnetic field (

The function of) is the angle of magnetization (θ), which is the angle between the easy axis of magnetization and the magnetization direction, and the angle of the external magnetic field (

A conversion step of converting the

)의 함수를, 이론식Magnetization angle (θ) and angle of external magnetic field (

) Function,

Computing the magnetic anisotropy constant (K) of the magnetic material by applying to,

H is the strength of the magnetic field applied to the magnetic material, M is preferably the saturation magnetization constant of the magnetic material.

According to the present invention, since the magnetic anisotropy constant is obtained by measuring an electrical signal such as the electrical resistance or the hall voltage of the magnetic body, it is not sensitive to external vibration and durability problems.

In addition, there is no limitation on the size of the sample. Rather, the smaller the size of the sample, the larger the size of the signal to be measured, and thus the measurement is easier.

In addition, if the area for measuring the electrical resistance of the sample is changed, only a specific area of the sample can be measured selectively.

Hereinafter, a magnetic anisotropy constant measuring apparatus according to a preferred embodiment of the present invention with reference to the accompanying drawings will be described in detail.

First, the magnetic anisotropy constant measuring apparatus according to the first embodiment for measuring the magnetic anisotropy constant of a sample having horizontal magnetic anisotropy will be described in detail.

1 is a view schematically showing the configuration of a magnetic anisotropy constant measuring apparatus according to a first embodiment of the present invention.

Referring to FIG. 1, the magnetic anisotropy constant measuring apparatus according to the first embodiment of the present invention includes a magnetic field generating unit 100, a rotating unit 200, a data measuring unit 300, and a magnetic anisotropy constant calculating unit 400. .

The magnetic field generating unit 100 may form a magnetic space by applying a uniform magnetic field in a predetermined space.

The rotating unit 200 may freely rotate the sample 500 about a predetermined axis in the magnetic space formed through the magnetic field generating unit 100. For example, the sample 500 may be fixed to be perpendicular to the rotation axis of the rotation part 200, and then rotated 360 degrees about the rotation axis in the anti-parallel direction from a direction parallel to the direction of the external magnetic field.

)에 따라 시료(500)의 저항값(R)을 측정한다. 여기서, 외부자기장 각도(

)는 시료(500)의 자화용이축과 시료(500)에 인가되는 자기장의 방향이 이루는 각도를 의미한다. The data measuring unit 300 has an external magnetic field angle (

), The resistance value R of the sample 500 is measured. Where the external magnetic field angle (

) Denotes an angle between the easy axis of magnetization of the sample 500 and the direction of the magnetic field applied to the sample 500.

)에 따라 시료(500)의 전압값을 측정한다. 데이터변환부는 전압측정부를 통해 측정된 전압값을 외부자기장의 각도(

)에 따른 저항값(R)으로 변환할 수 있다. 이때, 시료(500)에 공급되는 전류값을 알 수 있으므로, 데이터변환부는 옴의 법칙(V=IR)의 원리를 이용하여, 측정된 전압값을 저항값으로 변환할 수 있다. 따라서 데이트측정부(300)를 통해 외부자기장의 각도(

)에 따라 시료(500)의 저항값(R)을 측정할 수 있게 된다. The data measuring unit 300 may include a current supplying unit, a voltage measuring unit, and a data converting unit. As shown in FIG. 2, the current supply unit may be connected to electrodes at both ends of the sample 500, and supply a constant current to the sample 500 through the electrodes at both ends. The voltage measuring unit is also connected to the electrodes at both ends of the sample 500, and can measure the voltage of the sample 500 through the electrodes at both ends. At this time, the voltage measuring unit, the external magnetic field angle (

), The voltage value of the sample 500 is measured. The data converter converts the voltage value measured by the voltage measuring unit to the angle of the external magnetic field (

Can be converted into a resistance value (R). At this time, since the current value supplied to the sample 500 can be known, the data converter can convert the measured voltage value into a resistance value using the principle of Ohm's law (V = IR). Therefore, the angle of the external magnetic field through the date measuring unit 300 (

), The resistance value R of the sample 500 can be measured.

On the other hand, the data measuring unit 300 is not limited to the configuration of the current supply unit, the voltage measuring unit and the data conversion unit, as long as it can be configured to measure the electrical resistance of the material.

The sample 500 used in the first embodiment is a thin ribbon-shaped ferromagnetic nanowire having a width of about 600 nm, and has a horizontal magnetic anisotropy and has a permloy line structure. Here, the alloy refers to an alloy composed of about 80% nickel and 20% iron. This material is known to have almost no magnetic preference due to the atomic crystal structure. As a result, if you make a sample on the order of micro or nanometers, you will have a magnetic preference that depends only on the shape of the material. In particular, when this material is elongated, as shown in Fig. 2A, the magnetization states are aligned in the longitudinal direction.

In the first embodiment, as shown in FIG. 2B, anisotropic magnetoresistance was used to measure the magnetic anisotropy constant when the magnetization state of the sample sample structure 500 was changed from the longitudinal direction to the width direction. Anisotropic magnetoresistance is known as anisotropy magnetoresistance (AMR). The AMR phenomenon refers to a phenomenon in which the electric resistance value changes depending on the direction of the current and the magnetization direction inside the magnetic material. More specifically, when the direction of the current flowing through the magnetic material and the magnetization direction are parallel or anti-parallel, the electrical resistance of the material becomes maximum, and when it becomes vertical, the phenomenon becomes minimum. The resistance (R) of the magnetic body having horizontal magnetic anisotropy according to the AMR phenomenon may be expressed by the following formula.

In Equation 1, R is the resistance value of the magnetic body to be measured, R ₀ is the resistance value of the magnetic body when there is no external magnetic field, ΔR is the maximum change amount of the measured resistance value, and θ is the direction of the current flowing through the magnetic body. Means a magnetization angle which is an angle formed by the magnetization direction of the magnetic material. This resistance value R is a sin value of 0 when the magnetization angle θ becomes 0 degrees or 180 degrees (parallel or anti-parallel) and becomes a maximum of R ₀ when the magnetization angle θ is 0 degrees or 180 degrees (parallel or anti-parallel). It becomes 1 and it turns out that it becomes the minimum by R _< -> R. When the sample is rotated once, the resistance signal measured according to the rotation angle of the sample may appear as shown in FIG. 3.

As described above, according to the AMR phenomenon, the resistance value of the magnetic material having horizontal magnetic anisotropy shows a result depending on the angle formed between the direction of the current flowing through the magnetic material and the magnetization direction, that is, the magnetization angle θ. It can be seen that there is a dependency on sin ² θ.

)에 따라 시료(500)의 저항값(R)을 측정하였다.In the actual measurement, as shown in Fig. 4a, the external magnetic field angle (with the intensity H of the external magnetic field fixed at 2780 Oe)

), The resistance value R of the sample 500 was measured.

The magnetic anisotropy constant calculating unit 400 calculates the magnetic anisotropy constant K of the sample 500 using the resistance R of the sample 500 measured by the data measuring unit 300.

Prior to the description of the magnetic anisotropy constant calculating unit 400, the 'Stoner-Wohlfarth' terminal sphere theory for obtaining the magnetic anisotropy constant (R) will be briefly described.

라고 하면, 자성체의 에너지 E는 하기의 수식과 같이 나타낼 수 있다.The sample material used in the first embodiment of the present invention has a property that, if there is no external magnetic field, the magnetization direction of the material is aligned in one direction, and the magnetization direction is aligned with the biaxial axis for magnetization. do. In particular, the physical material is aligned in the magnetization direction in the longitudinal direction, when the external magnetic field is applied, the aligned magnetization direction is biased toward the external magnetic field. The angle between the magnetization axis and the magnetization direction of the magnetic material, θ, the intensity of the external magnetic field applied to the magnetic body, H, the saturation magnetization constant of the magnetic body, and the angle of the external magnetic field of the magnetic body.

In this case, the energy E of the magnetic body can be expressed by the following formula.

)'은 지만(Zeeman) 에너지를 의미하는 항으로, 외부 자기장과 시료의 자화방향이 어긋나면 어긋날수록 값이 커지게 된다. 수학식 2의 신호를 θ에 대하여 미분하고, 전체 값이 0인 경우를 찾게 되면, 에너지가 최소가 되는 곳으로써, 모든 변수들의 관계를 결정지을 수 있게 된다. 수학식 2를 미분해 주면, 다음 수식과 같이 나타낼 수 있다.In Equation 2, E is the energy value of the magnetic body, K is the magnetic anisotropy constant. In addition, the first term 'Ksin ² θ' means the magnetic anisotropy energy of the sample 500, and when the magnetization direction of the sample is the easy axis for magnetization (that is, the magnetization angle θ is 0 degrees or 180 degrees). If the magnetization angle θ is vertical (that is, when θ is 90 degrees or 270 degrees), the maximum is K. Second term 'HMcos (θ-

The term 'Zeeman' means energy, and the larger the value is, the more the magnetic field is misaligned with the external magnetic field. When the signal of Equation 2 is differentiated with respect to θ, and the case where the total value is 0 is found, the relationship between all variables can be determined as the energy is minimized. If the equation 2 is not decomposed, it can be expressed as the following equation.

, M, H는 이미 알고 있는 값이다. 따라서, 수학식 3을 참조하면, 자기이방성상수(K)가 고정된 상태에서 외부 자기장 각도(

)와 자화각도(θ)의 관계를 알 수 있으므로, 측정된 시료의 저항값(R)을 이용하여 자기이방성상수(K)를 구하면 된다. 자기이방성상수(K)를 구하기 위해서는, 시료의 자화방향이 어디인가, 즉, 자화각도(θ)와 외부 자기장 각도(

)에 대하여 알아야 한다. 여기서, 도 3을 통해 설명한 저항신호는, 자화각도(θ)에 따른 저항값에 대한 신호이며, 외부자기장의 크기(H)와 각도(

)에 따른 신호가 아님을 유의해야 한다. In actual measurement, the direction, magnitude, and saturation magnetization of the external magnetic field are also known.

, M and H are known values. Therefore, referring to Equation 3, the external magnetic field angle (A) is fixed while the magnetic anisotropy constant K is fixed.

) And the magnetization angle (θ) can be known, so the magnetic anisotropy constant (K) can be obtained using the measured resistance (R) of the sample. In order to find the magnetic anisotropy constant (K), where is the magnetization direction of the sample, that is, the magnetization angle θ and the external magnetic field angle (

You should know Here, the resistance signal described with reference to FIG. 3 is a signal for the resistance value according to the magnetization angle θ, and the magnitude (H) and the angle (

Note that this is not a signal according to).

의 관계로 표준화할 수 있다. 즉, 측정된 결과는 저항값(R)과 외부자기장 각도(

)의 함수로 나타낼 수 있는 데이터이므로, 수학식 3의 이론식에 적용하기 위해서는, 측정된 데이터를 자화각도(R)와 외부자기장의 각도(

)와의 대응관계를 갖는 데이터로 바꿔줄 필요가 있다. 이때, 측정되는 저항값(R), 측정된 저항값(R)의 최대 변화량(△R), 및 외부 자기장이 없을 경우의 저항값(R₀)은 측정을 통해 알 수 있다. 결국, 외부자기장의 각도(

)에 따른 R, △R 및 R₀을

에 대입하면, 외부자기장의 각도(

)에 따른 자화각도(θ)를 알 수 있으며, 보다 구체적으로, sin²θ=f(

)에 대한 함수를 얻을 수 있게 된다.The magnetic anisotropy constant calculating unit 400 first measures the measured data.

Can be standardized. That is, the measured result is the resistance value (R) and the external magnetic field angle (

Since the data can be expressed as a function of), in order to apply to the equation of Equation 3, the measured data is converted to the magnetization angle R and the angle of the external magnetic field (

You need to replace it with data that has a corresponding relationship with). In this case, the measured resistance value R, the maximum change amount ΔR of the measured resistance value R, and the resistance value R _{0 in the} absence of an external magnetic field may be known through the measurement. Finally, the angle of the external magnetic field (

R, ΔR and R _{0 according} to

If you substitute, the angle of the external magnetic field (

Magnetization angle (θ) according to), more specifically, sin ² θ = f (

You can get a function for).

When the standardization process is performed in this manner, a result as shown in FIG. 4B can be obtained.

)와 자화각도(θ)의 관계를 알 수 있다. 즉, 수학식 3을 통해 나타낸 이론식은 외부자기장 각도(

)와, sin²θ의 관계로 나타내 줄 수 있으며, 이를 그래프로 나타낼 경우, 도 5에 도시된 바와 같이 나타낼 수 있다. 도 5에 도시된 그래프는 자기이방성상수값(K)이 바뀜에 따라 그 형태가 조금씩 바뀌게 된다. 결국, 여러 형태로 나타내어지는 그래프 중 표준화된 데이터 그래프와 가장 잘 겹치는 그래프의 자기이방성상수(K)를 찾음으로써, 시료(500)의 자기이방성상수값(K)을 구하게 된다.Next, the magnetic anisotropy constant K is calculated by applying the standardized data to the equation of Equation 3. In the formula of Equation 3, since the strength H of the external magnetic field and the saturation magnetization value M of the sample 500 are known, the magnetic anisotropy constant value K is changed while the magnetic anisotropy constant value K is changed. ), The angle of the external magnetic field (

) And the angle of magnetization (θ). That is, the equation represented by Equation 3 is the external magnetic field angle (

) And sin ² θ, and this may be represented as shown in FIG. 5. The shape of the graph shown in FIG. 5 changes little by little as the magnetic anisotropy constant K is changed. As a result, the magnetic anisotropy constant K of the sample 500 is obtained by finding the magnetic anisotropy constant K of the graph that most overlaps with the standardized data graph among the graphs represented in various forms.

FIG. 6 is a diagram illustrating a theoretical calculation graph calculated using an experimental data graph and a 'Stoner-Wohlfarth' model measured according to a first embodiment of the present invention.

Referring to FIG. 6, when the experimental data graph measured according to the first embodiment of the present invention is fitted with a theoretical calculation graph calculated by a 'Stoner-Wohlfarth' model, the theoretical data well overlaps with the experimental data graph. A calculation graph exists. Therefore, it can be seen that the magnetic anisotropy constant (K) that fits the experimental data exists in the theoretical calculation.

The magnetic anisotropy constant measuring device according to the first embodiment of the present invention is not sensitive to the problems of external vibration and durability because it measures an electrical signal, that is, an electrical resistance, instead of measuring a force generated in a magnetized state of the magnetic body.

In addition, since the conventional torque magnetometer measures the actual force, there is a limit to reducing the size of the sample, the magnetic anisotropy constant measuring device of the present invention is not limited to the size of the sample, rather the electrical resistance measured as the size of the sample Since the size of the becomes larger, the measurement is easier.

In addition, if the area for measuring the electrical resistance of the sample is changed, only the specific area of the sample can be measured selectively.

Hereinafter, the magnetic anisotropy constant measuring apparatus according to the second embodiment for measuring the magnetic anisotropy constant of the sample having perpendicular magnetic anisotropy will be described in detail.

1 is a view schematically showing the configuration of a magnetic anisotropy constant measuring apparatus according to a second embodiment of the present invention.

Referring to FIG. 1, an apparatus for measuring magnetic anisotropy according to a second embodiment of the present invention includes a magnetic field generating unit 100, a rotating unit 200, a data measuring unit 300, and a magnetic anisotropic constant calculating unit 400. .

The magnetic field generating unit 100 may form a magnetic space by applying a uniform magnetic field in a predetermined space.

The rotating unit 200 may freely rotate the sample 500 about a predetermined axis in the magnetic space formed by the magnetic field generating unit 100. For example, the sample 500 may be fixed to be perpendicular to the rotation axis of the rotation part 200, and then rotated 360 degrees about the rotation axis in the anti-parallel direction from a direction parallel to the direction of the external magnetic field.

)에 따라 시료(500)의 홀 전압값(V_H)을 측정한다. 여기서, 외부자기장 각도(

)는 시료(500)의 자화용이축과, 시료(500)에 인가되는 자기장의 방향이 이루는 각도를 의미한다. The data measuring unit 300 has an external magnetic field angle (

), The Hall voltage value (V _H ) of the sample 500 is measured. Where the external magnetic field angle (

) Denotes an angle formed between the easy axis of magnetization of the sample 500 and the direction of the magnetic field applied to the sample 500.

)에 따른 홀 전압(V_H)을 측정할 수 있다.The data measuring unit 300 may include a current supply unit and a voltage measurer. 7 and 10, the current supply unit may be connected to the electrodes 510 of the first both ends of the sample 500, and supply a constant current through the electrodes 510 of the first both ends. The voltage measuring unit is connected to the electrodes 520 of the second both ends that are perpendicular to the electrode 510 of the first both ends, and the angle of the external magnetic field through the electrodes 520 of the second both ends.

), The Hall voltage (V _H ) can be measured.

The sample 500 used in the second embodiment is a CoFe ferromagnetic thin film. This material has a perpendicular magnetic anisotropy and is known as a PMA (perpendicular magnetic anisotropy) material. This PMA sample has a magnetization direction perpendicular to the plane direction, as shown in Fig. 7A.

In the second embodiment, the magnetic anisotropy constant is measured when the magnetization state perpendicular to the plane direction is changed to the horizontal magnetization state as shown in FIG. 7B by using the spin hole phenomenon. . The spin hole phenomenon is called the 'spin hall effect' and uses the principle of Lorentz force. Lorentz's force refers to a phenomenon in which force acts in a direction perpendicular to the direction of movement and magnetic field of electrons moving in the magnetic space. As shown in FIG. 8, when a constant current is supplied to the perpendicular magnetic sample, electrons move (or holes move in the current direction) in a direction opposite to the current direction. When a magnetic field is applied, a force acts in a direction perpendicular to the current direction and the magnetic field direction. As the direction of movement of the electrons (or the direction of movement of the holes) changes in the direction of the force generated in this way, the electrons accumulate on one side of the sample. As a result, a voltage difference, that is, a hall voltage, is generated at both ends of the sample. The hole voltage V _H of the magnetic material having perpendicular magnetic anisotropy according to the spin hole phenomenon can be expressed by the following formula.

In Equation 4, V _H is the measured Hall voltage value (V _H ), R is the proportional constant, I is the current value to be supplied, M is the saturation magnetization constant of the magnetic material, θ and the direction of the current flowing through the sample It means the magnetization angle (theta) which is the angle which the magnetization direction of a sample makes. Here, the Hall voltage value (V _H ), when the magnetization angle rotates once, may appear as shown in FIG.

)에 따라 수직자기이방성을 갖는 자성체의 홀 전압값(V_H)을 측정한 결과를 나타낸 그래프이다.As described above, according to the spin hole phenomenon, the Hall voltage value V _H of the magnetic body having the perpendicular magnetic anisotropy shows a result depending on the magnetization angle θ, and also depends on sin θ. . 11 is the angle of the external magnetic field through the experiment (

) Is a graph showing the result of measuring the Hall voltage value (V _H ) of a magnetic material having perpendicular magnetic anisotropy according to).

)에 따라 시료(500)의 홀전압(V_H)을 측정하였다.In the actual measurement, the angle of the external magnetic field (with the magnitude and direction of the external magnetic field fixed)

), The Hall voltage (V _H ) of the sample 500 was measured.

The magnetic anisotropy constant calculating unit 400 calculates the magnetic anisotropy constant K of the sample 500 using the Hall voltage value V _H measured by the data measuring unit 300.

Prior to the description of the magnetic anisotropy constant calculating unit 400, the 'Stoner-Wohlfarth' terminal sphere theory for obtaining the magnetic anisotropy constant (K) will be briefly described.

라고 하면, 자성체의 에너지 E는 하기의 수식과 같이 나타낼 수 있다.The PMA material, which is a sample used in the second embodiment of the present invention, has a property that the magnetization direction of the material is aligned in one direction when there is no external magnetic field, and the magnetization direction is aligned with the biaxial axis for magnetization. . In particular, the PMA material is aligned in the magnetization direction in a direction perpendicular to the plane, and when the magnetic field is applied from the outside, the aligned magnetization direction is biased toward the external magnetic field. The angle between the PMA material, ie, the easy axis and the direction of magnetization of the magnetic body is θ, the intensity of the external magnetic field applied to the magnetic body is H, the saturation magnetization constant of the magnetic body is M, the angle of the magnetic axis and the external magnetic field of the magnetic body.

In this case, the energy E of the magnetic body can be expressed by the following formula.

)'은 지만(Zeeman) 에너지를 의미하는 항으로, 외부 자기장과 시료의 자화방향이 어긋나면 어긋날수록 값이 커지게 된다.In Equation 5, E is the energy value of the magnetic body, K is the magnetic anisotropy constant, and the first term 'Ksin ² θ' is a term representing the magnetic anisotropy energy of the sample 500, the magnetization of the sample When the direction is the easy axis for magnetization (i.e., the angle of magnetization θ is 0 degrees or 180 degrees), it becomes 0, and when the magnetization angle θ is vertical (i.e., θ is 90 degrees or 270 degrees) K is the maximum. Second term 'HMcos (θ-

The term 'Zeeman' means energy, and the larger the value is, the more the magnetic field is misaligned with the external magnetic field.

When the signal of Equation 5 is differentiated with respect to θ, and the case where the total value is 0 is found, the relationship between all variables can be determined as the energy is minimized. If the equation 5 is not decomposed, it can be expressed as the following equation.

, M, H는 이미 알고 있는 값이다. 따라서, 수학식 6을 참조하면, 자기이방성상수(K)가 고정된 상태에서 외부 자기장 각도(

)와 자화각도(θ)의 관계를 알 수 있 으므로 측정된 시료의 홀 전압값(V_H)을 이용하여 자기이방성상수(K)를 구하면 된다. 자기이방성상수(K)를 구하기 위해서는, 시료의 자화방향이 어디인가, 즉, 자화각도(θ)와 외부 자기장 각도(

)에 대하여 알아야 한다. 도 9을 통해 설명한 홀 전압 신호는 자화각도(θ)에 따른 신호이며, 외부자기장의 크기(H)와 각도(

)에 따른 신호가 아님을 유의해야 한다. In actual measurement, the direction, magnitude, and saturation magnetization of the external magnetic field are also known.

, M and H are known values. Therefore, referring to Equation 6, when the magnetic anisotropy constant K is fixed, the external magnetic field angle (

) And the magnetization angle (θ), so the magnetic anisotropy (K) can be obtained using the measured Hall voltage (V _H ). In order to find the magnetic anisotropy constant (K), where is the magnetization direction of the sample, that is, the magnetization angle θ and the external magnetic field angle (

You should know The Hall voltage signal described with reference to FIG. 9 is a signal according to the magnetization angle θ, and the magnitude (H) and the angle (

Note that this is not a signal according to).

의 관계로 표준화할 수 있다. 즉, 측정된 결과는 홀 전압값(V_H)과 외부자기장 각도(

)의 함수로 나타낼 수 있는 데이터이므로, 수학식 6의 이론식에 적용하기 위해서는, 측정된 데이터를 자화각도(R)와 외부자기장의 각도(

)와의 대응관계를 갖는 데이터로 바꿔줄 필요가 있다. The magnetic anisotropy constant calculating unit 400 measures the measured data

Can be standardized. That is, the measured result is the Hall voltage value (V _H ) and the external magnetic field angle (

Since the data can be expressed as a function of), in order to apply to the equation of Equation 6, the measured data is converted to the magnetization angle R and the angle of the external magnetic field (

You need to replace it with data that has a corresponding relationship with).

) 범위를 한정할 필요가 있다. 그 이유는, 홀 효과의 경우, 외부 자기장의 각도(

)가 90도 근처에서 자화역전이 일어나므로, 자화역전이 일어나는 현상까지 이론식에 적용할 수 없기 때문이다. 도 11은 수직자기이방성을 나타내는 CoFe 강자성 박막에 3 KOe 세기의 자기장을 인가하여 홀 전압(V_H)을 측정한 결과를 나타낸 그래프이며, 도 12는 도 11에 도시된 측정 결과를 외부 자기장의 각도(

) 범위를 -50도에서 50도까지로 한정하여 나타낸 그래프이다. Prior to this, when the Hall voltage is measured, the angle of the external magnetic field (

It is necessary to limit the range. The reason for this is that in the Hall effect, the angle of the external magnetic field (

This is because the magnetization reversal occurs at around 90 degrees, so it cannot be applied to the theory until the magnetization reversal occurs. FIG. 11 is a graph illustrating a result of measuring Hall voltage (V _H ) by applying a magnetic field of 3 KOe intensity to a CoFe ferromagnetic thin film exhibiting perpendicular magnetic anisotropy. FIG. 12 is an angle of an external magnetic field. (

) It is a graph limited to the range from -50 to 50 degrees.

) 범위가 한정된 홀 전압(V_H)과 외부자기장 각도(

)의 함수를 자화각도(θ)와 외부자기장 각도(

) 의 함수로 바꿔준다. 즉, 측정된 홀 전압값(V_H)을 이용하여

의 관계로 표준화하면, 외부자기장의 각도(

)와 자화각도(θ)의 함수로 바꿔줄 수 있게 된다. 이때, 비례상수(R), 전류값(I) 및 포화자화값(M)은 이미 알고 있는 고정된 상수이므로, 외부자기장의 각도(

)에 따른 V_H과 고정된 상수인 R, I 및 M을

에 대입하면, 외부자기장의 각도(

)에 따른 자화각도(θ)를 알 수 있으며, 보다 구체적으로, sinθ=f(

)에 대한 함수를 얻을 수 있게 된다.Next, the angle of the external magnetic field (

) Hall voltage with limited range (V _H ) and external magnetic field angle (

) Is a function of magnetization angle (θ) and external magnetic field angle (

To a function of). That is, using the measured Hall voltage value (V _H )

Normalized in relation to, the angle of the external magnetic field (

) And the angle of magnetization (θ). At this time, the proportional constant (R), the current value (I) and the saturation magnetization value (M) are known constant constants, so that the angle of the external magnetic field (

V _H according to) and the fixed constants R, I and M

If you substitute, the angle of the external magnetic field (

Magnetization angle (θ) according to), more specifically, sinθ = f (

You can get a function for).

)와 자화각도(θ)의 대응관계를 알 수 있도록 표준화된 데이터를 수학식 6의 이론식에 적용하여 자기이방성상수(K)를 구한다. 수학식 6의 이론식에 있어서, 외부자기장의 세기(H)와 시료(500)의 포화자화값(M)은 알고 있으므로, 자기이방성상수값(K)이 고정된 상태에서 외부자기장의 각도(

)와 자화각도(θ)의 관계를 알 수 있다. 즉, 수학식 6을 통해 나타낸 신호도 외부자기장의 각도(

)과 sinθ의 관계로 나타내 줄 수 있다. Next, the angle of the external magnetic field (

), And the magnetic anisotropy constant (K) is obtained by applying the standardized data to the equation of Equation 6 to know the correspondence between In the formula of Equation 6, since the strength H of the external magnetic field and the saturation magnetization value M of the sample 500 are known, the angle of the external magnetic field in the state where the magnetic anisotropy constant K is fixed (

) And the angle of magnetization (θ). That is, the signal represented by Equation 6 also has an angle of the external magnetic field (

) And sinθ.

Here, when the theoretical formula of Equation 6 is represented as a graph, the strength of the external magnetic field (H) and the saturation magnetization value (M) of the sample 500 are fixed constants. As the K) changes, the form appears slightly different. Therefore, the magnetic anisotropy constant (K) of the sample 500 is obtained by finding the magnetic anisotropy constant (K) of the graph that most overlaps with the standardized data graph among various types of graphs.

The magnetic anisotropy constant measuring device according to the second embodiment of the present invention is not sensitive to the problems of external vibration and durability because it measures an electrical signal, that is, a hall voltage, instead of measuring a force generated in a magnetized state of the magnetic body.

In addition, since the conventional torque magnetometer measures the actual force, there is a limit to reducing the size of the sample, the magnetic anisotropy constant measuring device of the present invention is not easy because the size of the sample, it is easier to measure.

FIG. 13 is a flowchart schematically illustrating a method of measuring magnetic anisotropy constants of magnetic bodies having horizontal magnetic anisotropy and vertical magnetic anisotropy according to an embodiment of the present invention.

Referring to FIG. 13, the method for measuring the magnetic anisotropy constant of a magnetic body having horizontal magnetic anisotropy according to the present invention includes applying a uniform magnetic field to form a magnetic space (S1), and forming a magnetic body in the magnetic space. Rotation step (S2) for rotating around a certain axis, a data measuring step (S3) for measuring the resistance value of the magnetic body according to the angle of the external magnetic field, which is the angle between the easy axis of magnetization of the magnetic body and the direction of the magnetic field applied to the magnetic body, And a magnetic anisotropy constant calculating step (S4) of calculating a magnetic anisotropy constant of the magnetic body by using the measured resistance value.

Since the method of measuring the magnetic anisotropy constant of the magnetic body having the horizontal magnetic anisotropy according to the present invention is the same as that of the detailed description of the apparatus for measuring the magnetic anisotropy constant according to the first embodiment described above, the horizontal magnetic anisotropy according to the present invention The detailed description of the method for measuring the magnetic anisotropy constant of the magnetic material having a magnetic field is replaced with the detailed description of the magnetic anisotropy constant measuring apparatus according to the first embodiment described above.

On the other hand, referring to Figure 13, the method for measuring the magnetic anisotropy constant of the magnetic body having a perpendicular magnetic anisotropy according to the present invention, the magnetic field applying step (S1) to form a magnetic space by applying a uniform magnetic field in the magnetic space A rotation step (S2) of rotating the magnetic body about a certain axis, and a data measuring step of measuring the Hall voltage value of the magnetic body according to the angle of the external magnetic field, which is an angle formed between the easy axis of magnetization of the magnetic body and the direction of the magnetic field applied to the magnetic body ( S3), and a magnetic anisotropy constant calculating step (S4) for calculating the magnetic anisotropy constant of the magnetic material using the measured Hall voltage value.

Since the method of measuring the magnetic anisotropy constant of the magnetic body having the perpendicular magnetic anisotropy according to the present invention is the same as that of the detailed description of the apparatus for measuring the magnetic anisotropy constant according to the second embodiment, the perpendicular magnetic anisotropy according to the present invention The detailed description of the method for measuring the magnetic anisotropy constant of the magnetic material having a magnetic field is replaced with the detailed description of the magnetic anisotropy constant measuring apparatus according to the second embodiment described above.

In the above, the present invention has been described in detail with respect to the apparatus and measuring method for measuring the magnetic anisotropy constant by measuring the electrical resistance or the Hall voltage of the magnetic material, not limited to this, magnetic anisotropy using the electrical signal generated in the magnetic state of the magnetic material It will be understood that the present invention can be applied to an anisotropic constant measuring device and a measuring method capable of measuring a constant.

Therefore, embodiments of the magnetic anisotropy constant measuring apparatus and measuring method using the above-described electrical resistance or hall voltage measurement are to be understood as illustrative and not limiting in all respects, and the scope of the present invention is described in detail above. The present invention is indicated by the following claims rather than by the description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention.

1 is a view showing a schematic configuration of a magnetic anisotropy constant measuring apparatus according to the present invention.

2 is a view showing the characteristics of the sample according to the first embodiment of the present invention.

3 is a graph conceptually showing anisotropic magnetoresistance of a magnetic body having horizontal magnetic anisotropy according to magnetization angle.

)에 따른 자성체의 저항값을 나타낸 그래프.4A is an angle of an external magnetic field measured according to the first embodiment of the present invention.

A graph showing the resistance value of the magnetic body according to).

)와의 관계로 표준화하여 나타낸 그래프.4B shows the measurement result shown in FIG. 4A using the magnetization angle θ and the angle of the external magnetic field (

Normalized graph in relation to).

)의 각도와의 관계로 나타낸 그래프.5 is a reference signal according to the terminal model is a magnetization angle (θ) and the external magnetic field (

A graph showing the relationship with the angle of).

FIG. 6 is a diagram illustrating a theoretical calculation graph calculated using an experimental data graph and a 'Stoner-Wohlfarth' model measured according to a first embodiment of the present invention.

7 is a view showing the characteristics of the sample according to the second embodiment of the present invention.

8 is a diagram conceptually showing a spin hole phenomenon used in a second embodiment of the present invention.

9 is a graph conceptually showing the Hall voltage of a magnetic material having perpendicular magnetic anisotropy according to the magnetization angle.

10 is a view showing an electrode connection method of a sample according to a second embodiment of the present invention.

)에 따른 자성체의 홀 전압을 나타낸 그래프.11 is an angle of the external magnetic field measured according to the second embodiment of the present invention (

The graph showing the Hall voltage of the magnetic material according to).

)를 한정하여 나타낸 홀 전압 신호를 나타낸 도면.12 is an angle of an external magnetic field in the measurement result of FIG.

Is a diagram showing a Hall voltage signal defined by &quot;

13 is a flow chart schematically showing a method for measuring magnetic anisotropy constants according to the first and second embodiments of the present invention.

Claims (12)

A device for measuring the magnetic anisotropy constant of a magnetic body having horizontal magnetic anisotropy, A magnetic field generator for forming a magnetic space by applying a uniform magnetic field; A rotating part rotating the magnetic material about a predetermined axis in the magnetic space; The angle of the external magnetic field, which is an angle formed between the easy axis of magnetization of the magnetic body and the direction of the magnetic field applied to the magnetic body (

A data measuring unit measuring a resistance value (R) of the magnetic material according to; And The angle of the measured external magnetic field (

Magnetic anisotropy constant calculating unit for calculating the magnetic anisotropy constant (K) of the magnetic material using the resistance value (R) according to Magnetic anisotropy constant measuring device comprising a. The method of claim 1, The data measuring unit, A current supply unit connected to electrodes of both ends of the magnetic body and supplying a constant current to the magnetic body through electrodes of both ends of the magnetic body; Is connected to the electrodes of both ends of the magnetic body, and measuring the voltage value of the magnetic material through the electrodes of both ends of the magnetic material, the angle of the external magnetic field (

A voltage measuring unit measuring a voltage value of the magnetic material according to; And The angle of the measured external magnetic field (

Voltage value according to the angle of the external magnetic field (

Magnetic anisotropy constant measuring device comprising a data conversion unit for converting into a resistance value (R) according to. The method of claim 1, The magnetic anisotropy constant calculating unit, The angle of the measured external magnetic field (

By using the resistance value R according to), the measured resistance value R and the angle of the external magnetic field (

Is a function of the magnetization easy axis of the magnetic body and the magnetization direction. The angle of magnetization (θ) and the angle of the external magnetic field (

To a function of), The angle of magnetization θ and the angle of the external magnetic field

) Function,

Is applied to calculate the magnetic anisotropy constant (K) of the magnetic material, H is the strength of the magnetic field applied to the magnetic material, Wherein M is a saturation magnetization constant of the magnetic material, magnetic anisotropy constant measuring apparatus. A device for measuring the magnetic anisotropy constant of a magnetic body having perpendicular magnetic anisotropy, A magnetic field generator for forming a magnetic space by applying a uniform magnetic field; A rotating part rotating the magnetic material about a predetermined axis in the magnetic space; The angle of the external magnetic field, which is an angle formed between the easy axis of magnetization of the magnetic body and the direction of the magnetic field applied to the magnetic body (

A data measuring unit measuring a Hall voltage value (V _H ) of the magnetic material according to; And The angle of the measured external magnetic field (

Magnetic anisotropy constant calculating unit for calculating the magnetic anisotropy constant (K) of the magnetic material using the Hall voltage value (V _H ) according to Magnetic anisotropy constant measuring device comprising a. The method of claim 4, wherein The data measuring unit, A current supply unit connected to the electrodes of the first both ends of the magnetic material and supplying a constant current to the magnetic material through the electrodes of the first both ends; And A hole voltage value (V _H ) of the magnetic material is measured through the electrodes of the second both ends and connected to the electrodes of the second both ends that are perpendicular to the electrodes of the first both ends of the magnetic material. Magnetic field angle (

Magnetic anisotropy constant measuring apparatus comprising a voltage measuring unit for measuring the Hall voltage value (V _H ) of the magnetic material according to). The method of claim 4, wherein The magnetic anisotropy constant calculating unit, The angle of the measured external magnetic field (

By using the Hall voltage value according to), the measured angle of the Hall voltage (V _H ) and the external magnetic field (

Is a function of the magnetization easy axis of the magnetic body and the magnetization direction. The angle of magnetization (θ) and the angle of the external magnetic field (

To a function of), The angle of magnetization θ and the angle of the external magnetic field (

) Function,

Is applied to calculate the magnetic anisotropy constant (K) of the magnetic material, H is the strength of the magnetic field applied to the magnetic material, Wherein M is a saturation magnetization constant of the magnetic material, magnetic anisotropy constant measuring apparatus. In the method for measuring the magnetic anisotropy constant of a magnetic material having horizontal magnetic anisotropy, A magnetic field applying step of applying a uniform magnetic field to form a magnetic space; A rotation step of rotating the magnetic material about a predetermined axis in the magnetic space; The angle of the external magnetic field, which is an angle formed between the easy axis of magnetization of the magnetic body and the direction of the magnetic field applied to the magnetic body (

A data measuring step of measuring a resistance value R of the magnetic material according to; And The angle of the measured external magnetic field (

Magnetic anisotropy constant calculating step of calculating the magnetic anisotropy constant (K) of the magnetic material using the resistance value R according to Magnetic anisotropy constant measuring method comprising a. The method of claim 7, wherein The data measurement step, A current supplying step of supplying a constant current to the magnetic material through electrodes at both ends of the magnetic material; Measuring the voltage of the magnetic material through the electrodes of both ends of the magnetic material, the angle of the external magnetic field (

A voltage measuring step of measuring a voltage value of the magnetic material according to; And The angle of the measured external magnetic field (

The voltage value according to the angle of the external magnetic field (

Method for measuring the magnetic anisotropy constant, comprising a data conversion step of converting the resistance value (R) according to). The method of claim 7, wherein The magnetic anisotropy constant calculating step, The angle of the measured external magnetic field (

By using the resistance value R according to), the measured resistance value R and the angle of the external magnetic field (

Is a function of the magnetization easy axis of the magnetic body and the magnetization direction. The angle of magnetization (θ) and the angle of the external magnetic field (

A conversion step of converting the function into; And The angle of magnetization θ and the angle of the external magnetic field (

) Function,

Comprising a calculation step of calculating the magnetic anisotropy constant (K) of the magnetic material by applying to, H is the strength of the magnetic field applied to the magnetic material, M is a saturation magnetization constant of the magnetic material, magnetic anisotropy constant measuring method. In the method for measuring the magnetic anisotropy constant of a magnetic body having perpendicular magnetic anisotropy, A magnetic field applying step of applying a uniform magnetic field to form a magnetic space; A rotation step of rotating the magnetic material about a predetermined axis in the magnetic space; The angle of the external magnetic field, which is an angle formed between the easy axis of magnetization of the magnetic body and the direction of the magnetic field applied to the magnetic body (

A data measuring step of measuring a hall voltage value (V _H ) of the magnetic material according to; And The angle of the measured external magnetic field (

Magnetic anisotropy constant calculating step of calculating the magnetic anisotropy constant (K) of the magnetic material using the Hall voltage value (V _H ) according to Magnetic anisotropy constant measuring method comprising a. The method of claim 10, The data measurement step, A current supplying step of supplying a constant current to the magnetic body through electrodes of the first both ends of the magnetic body; And The Hall voltage value (V _H ) of the magnetic material is measured through the electrodes of the second both ends that are perpendicular to the electrodes of the first both ends of the magnetic material, and the angle of the external magnetic field (

And a voltage measuring step of measuring a Hall voltage value (V _H ) of the magnetic material. The method of claim 10, The magnetic anisotropy constant calculating step, The angle of the measured external magnetic field (

By using the Hall voltage value according to), the measured angle of the Hall voltage (V _H ) and the external magnetic field (

Is a function of the magnetization easy axis of the magnetic body and the magnetization direction. The angle of magnetization (θ) and the angle of the external magnetic field (

A conversion step of converting the function into; And The angle of magnetization θ and the angle of the external magnetic field (

) Function,

Comprising a calculation step of calculating the magnetic anisotropy constant (K) of the magnetic material by applying to, H is the strength of the magnetic field applied to the magnetic material, M is a saturation magnetization constant of the magnetic body, magnetic anisotropy constant measuring method.

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