CN100553030C - Electric field-tunable negative magnetic permeability part and preparation method based on ferroelectric ceramic grain - Google Patents

Abstract

Based on the electric field-tunable negative magnetic permeability part and the preparation method of ferroelectric ceramic grain, this device is by two metal electrode boards that be arranged in parallel, and stacked polytetrafluoroethylene template, ferroelectric ceramic grain and the DC power supply of polylith that is arranged between two battery lead plates formed; Every polytetrafluoroethylene template is provided with array of circular apertures, and ferroelectric ceramic grain embeds in the circular hole.This device can make electromagnetic wave in a certain frequency range very strong magnetic resonance take place, and has isotropism negative magnetoconductivity effect near magnetic resonance, utilizes electric field the regulating characteristics of ferroelectric ceramic grain dielectric constant to be realized the Modulatory character of its negative magnetoconductivity.The present invention has given intelligent characteristic for left-handed materials, and will be applied to photoelectric device and communication fields such as variable band-pass filter, adjustable negative refraction rate flat-plate lens, adjustable stealthy device.

Description

Electric field-tunable negative magnetic permeability part and preparation method based on ferroelectric ceramic grain

Technical field

The present invention relates to a kind of isotropism negative magnetic permeability part, particularly a kind of electric field-tunable negative magnetic permeability part based on ferroelectric ceramic grain.

Background technology

(Left-handed metamaterials, research LHMs) is forward position and the hot issue in the research fields such as current physics, materialogy and electromagnetism to left-handed materials, has a wide range of applications.Simultaneously less than zero, the typical structure of realizing LHMs usually is the composite construction of metal openings resonant ring (SRRs) and metal wire in a certain frequency range for the effective dielectric constant of LHMs and magnetic permeability.The magnetic permeability of the SRRs array of periodic arrangement near its magnetic resonance frequencies in the narrower frequency range for negative, and the Metallic rod array of periodic arrangement has negative dielectric constant in the broad frequency range less than its plasma frequency.Thereby, the not plyability that dielectric constant and magnetic permeability are realized, the realization that causes negative magnetoconductivity plays crucial effects for the preparation of LHMs.

Usually, the magnetic response of metal structure unit is mainly determined by its equivalent capacity and equivalent inductance, promptly is subjected to the influence of its physical dimension, environment dielectric constant and magnetic permeability.Construction unit by the design different geometrical size is realized the magnetic resonance of required frequency range with the medium substrate of selecting differing dielectric constant for use, thereby realizes negative magnetic permeability.But this method is a kind of passive type design, has a lot of shortcomings.Once design and processing, its magnetic response frequency and left hand frequency range are just immutable, have limited its practical ranges as the construction unit of LHMs.Thereby, design a kind of dynamic-tuning LHMs and just seem particularly important.

In addition, be anisotropic based on the electromagnetic response characteristic of the LHMs of metal structure unit, promptly only on some directions, have negative electromagnetic parameter, limited its range of application greatly.Realize that infrared and research visible light wave range LHMs has obtained gratifying progress although utilize the metal structure unit, but, utilize existing micro-processing technology to prepare comparatively difficulty and costing an arm and a leg of micro nano structure unit because the geometry of metal structure unit is complicated usually.Simultaneously, metal is very big in infrared and loss visible light wave range, thereby has limited the realization of its electromagnetic performance.

Summary of the invention

The objective of the invention is to utilize ferroelectric ceramic grain responsive dielectric response behavior under same electric field not, a kind of electric field-tunable isotropism negative magnetic permeability part based on ferroelectric ceramic grain and preparation method thereof is provided.

Technical scheme of the present invention is as follows:

A kind of electric field-tunable isotropism negative magnetic permeability part based on ferroelectric ceramic grain, it is characterized in that: described device is by two metal electrode boards that be arranged in parallel, be arranged on the stacked polytetrafluoroethylene template of polylith between two battery lead plates, ferroelectric ceramic grain and DC power supply are formed; Every polytetrafluoroethylene template is provided with array of circular apertures, and described ferroelectric ceramic grain embeds in the circular hole; This devices use electric field is realized the tunability of described negative magnetoconductivity to the regulating characteristics of ferroelectric ceramic grain dielectric constant.

The dielectric constant of ferroelectric ceramic grain of the present invention is 600～2000; Array of circular apertures on the described polytetrafluoroethylene template is square profile and lattice constant is 1.0～3.0mm.Ferroelectric ceramic cubic block or diameter that the described ferroelectric ceramic grain employing length of side is 0.45～1.8mm are 0.5～2.6mm ferroelectric ceramic ball.

The present invention also provides a kind of preparation method of the electric field-tunable isotropism negative magnetic permeability part based on ferroelectric ceramic grain, and this method comprises the steps:

1) utilize ceramic size curtain coating technology, with ferroelectric ceramic powder and MgO powder by mass percentage concentration 0～20% mix and be made into slurry and carry out curtain coating with organic solvent, obtain the cast sheet of different-thickness;

2) cast sheet is slit into cubic block that the length of side is 0.5～2.3mm and carry out binder removal at 300～500 ℃, at last 1300～1500 ℃ of sintering 3～6 hours, obtain the length of side and be the ferroelectric ceramic cubic block of 0.45～1.8mm or it is worn into the ferroelectric ceramic ball that diameter is 0.5～2.6mm.

3) prepare array of circular apertures on the thick polyfluortetraethylene plate of 1.0～3.0mm, circular hole is square profile and lattice constant is 1.0～3.0mm; Ceramic cubic block or Ceramic Balls are embedded in the circular hole of polytetrafluoroethylene template, make two-dimentional ceramic particle array;

4) the polyfluortetraethylene plate circular hole aligning that will be embedded with ceramic particle again carries out stacked bonding, obtains the three-dimensional ceramic array of particles; At last three-dimensional ceramic array of particles and two metal electrode boards that be arranged in parallel are bonded together;

5) regulate the dielectric constant of ferroelectric ceramic grain by the size of regulating power electrical field, thereby obtain electric field-tunable isotropism negative magnetic permeability part.

In the said method, described ferroelectric ceramic powder preferably adopts Ba _xSr _1-xTiO ₃Powder, wherein x is 0.4～0.6.

The present invention has the following advantages and the high-lighting effect: the present invention utilizes ceramic particle responsive dielectric response behavior under same electric field not, realizes tunable negative magnetoconductivity.This device can make electromagnetic wave in a certain frequency range very strong magnetic resonance take place, and has isotropism negative magnetoconductivity effect near magnetic resonance, utilizes electric field the regulating characteristics of ferroelectric ceramic grain dielectric constant to be realized the Modulatory character of its negative magnetoconductivity.This invention is that left-handed materials has been given intelligent characteristic, and will be applied to photoelectric device and communication fields such as variable band-pass filter, adjustable negative refraction rate flat-plate lens, adjustable stealthy device.This invention has important academic significance and using value.

Description of drawings

Fig. 1 is based on the electric field-tunable negative magnetic permeability part schematic diagram of ferroelectric ceramic grain.

Fig. 2 barium strontium titanate (Ba _0.5Sr _0.5TiO ₃) dielectric constant of ferroelectric ceramic is with the variation relation of extra electric field.

Fig. 3 is based on the electric field-tunable microwave transmission curve of the electric field-tunable negative magnetic permeability part of ferroelectric ceramic grain (length of side is 1.00mm).

Fig. 4 is based on the electric field-tunable permeability curcve of the electric field-tunable negative magnetic permeability part of ferroelectric ceramic grain (length of side is 1.00mm).

Fig. 5 is based on the electric field-tunable microwave transmission curve of the electric field-tunable negative magnetic permeability part of ferroelectric ceramic grain (length of side is 0.70mm).

Among the figure: the 1-ferroelectric ceramic grain; The 2-polyfluortetraethylene plate; The 3-circular hole; The 4-metal electrode; The 5-incident electromagnetic wave; 6-outgoing electromagnetic wave.

Embodiment

Fig. 1 is the electric field-tunable negative magnetic permeability part structural representation based on ferroelectric ceramic grain provided by the invention, this device is by two metal electrode boards that be arranged in parallel 4, be arranged on the stacked polytetrafluoroethylene template 2 of polylith between two battery lead plates, ferroelectric ceramic grain 1 and DC power supply are formed; Every polytetrafluoroethylene template is provided with array of circular apertures 3, and each circular hole is embedded with ferroelectric ceramic grain 1; This device can make electromagnetic wave in a certain frequency range very strong magnetic resonance take place, and has isotropism negative magnetoconductivity effect near magnetic resonance, utilizes electric field the regulating characteristics of ferroelectric ceramic grain dielectric constant to be realized the Modulatory character of its negative magnetoconductivity.

Working mechanism of the present invention is as follows:

The present invention is a kind of electric field-tunable negative magnetic permeability part based on ferroelectric ceramic grain, and its core is to utilize the dielectric constant of ferroelectric ceramic grain to change with electric field change, thereby its negative magnetoconductivity can be regulated and control by electric field.

Lewin has utilized the theoretical and electromagnetic scattering theoretical research of active medium and has been dispersed in the another kind of continuous medium and the electromagnetic response behavior of the complex media that forms draws effective dielectric constant and effective permeability and satisfies following theoretical expression by loss-free dielectric/magnetic particle ball:

${\mathrm{\ϵ}}_{\mathrm{eff}}={\mathrm{\ϵ}}_h[1+\frac{3v}{\frac{F\left(\mathrm{\θ}\right)+{2K}_e}{F\left(\mathrm{\θ}\right)-K_e}-v}]---\left(1\right)$

${\mathrm{\μ}}_{\mathrm{eff}}={\mathrm{\μ}}_h[1+\frac{3v}{\frac{F\left(\mathrm{\θ}\right)+{2K}_m}{F\left(\mathrm{\θ}\right)-K_m}-v}]---\left(2\right)$

$K_e=\frac{{\mathrm{\ϵ}}_h}{{\mathrm{\ϵ}}_p}---\left(3\right)$

$K_m=\frac{{\mathrm{\μ}}_h}{{\mathrm{\μ}}_p}---\left(4\right)$

$v=\frac{4}{3}\mathrm{\π}{\left(\frac{r}{s}\right)}^3---\left(5\right)$

$F\left(\mathrm{\θ}\right)=\frac{2(\sin \mathrm{\θ}-\mathrm{\θ}\cos \mathrm{\θ})}{({\mathrm{\θ}}^2-1)\sin \mathrm{\θ}+\mathrm{\θ}\cos \mathrm{\θ}}---\left(6\right)$

$\mathrm{\θ}=k_{0}r\sqrt{{\mathrm{\ϵ}}_p{\mathrm{\μ}}_p}---\left(7\right)$

Wherein, ε _pAnd μ _pBe respectively the relative dielectric constant and the magnetic permeability of particle ball, ε _hAnd μ _hBe respectively the relative dielectric constant and the magnetic permeability of continuous medium, r is the radius of a ball, and s is a lattice constant, k ₀Wave vector for free space.The applicable elements of active medium theory is ε _p＞＞ε _h, thereby above various just meaningful must satisfy long wavelength's approximate condition the time.

When the denominator of (6) formula was zero, F (θ) will become infinity, and promptly F (θ) is a resonance function.When θ got some particular value, F (θ) may be negative value, thereby caused (1) and (2) formula also may be less than zero, and promptly effective dielectric constant and magnetic permeability are less than zero.Thereby, just can make that by selecting suitable material (size of ball, dielectric constant and magnetic permeability etc.) its magnetic permeability or dielectric constant are negative in a certain frequency range.The generation of this negative magnetoconductivity is that this displacement current can be equivalent to a magnetic dipole, thereby produces due to the very strong magnetic resonance because electromagnetic field has been induced annular displacement current in dielectric grain.This magnetic resonance is corresponding to the 1st grade of Mie resonance mode.

The dielectric constant of ferroelectric ceramic grain changes with the variation of extra electric field, temperature, stress etc., thereby can regulate its dielectric property by changing electric field, and then realizes the adjustable characteristic of electric field of negative magnetoconductivity.The dielectric constant of ferroelectric ceramic with the variation relation of extra electric field is:

ε _r＝ε _r0/(1+AE ²) ^1/3

Wherein, ε _R0And ε _rBe respectively the relative dielectric constant under null field and the electric field E effect, A is phenomenological coefficient a and ε _R0Product, relevant with concrete material.

At first prepare ferroelectric ceramic grain.Barium strontium titanate (Ba _xSr _1-xTiO ₃(BST), x=0.4～0.6) be a kind of ferroelectric material, have high micro-wave dielectric constant and low-loss, have the dielectric adjustable characteristic simultaneously again.Adopt synthesis by solid state reaction to prepare the BST powder.This method adopts highly purified BaCO ₃, SrCO ₃And TiO ₂Be raw material, react with following equation and make the BST powder.

xBaCO ₃+(1-x)SrCO ₃+TiO ₂＝Ba _xSr _1-xTiO ₃+CO ₂↑

With BaCO ₃, SrCO ₃And TiO ₂Mix by above proportioning, through ball milling, dry, sieve after, 1100～1300 ℃ of calcinings 3～6 hours, and then ball milling, that oven dry makes the BST powder was stand-by.

Utilize ceramic size curtain coating technology, the BST powder mixed and be made into slurry with organic solvent with a certain amount of MgO powder (mass percent concentration of MgO powder is 0～20%) carry out curtain coating, obtain the cast sheet of different-thickness, then cast sheet is cut into cubic block that the length of side is 0.5～2.3mm and carry out binder removal at 300～500 ℃, at last 1300～1500 ℃ of sintering 3～6 hours, the ferroelectric ceramic cubic block 1 or the ball milling that obtain the length of side and be 0.45～1.8mm densification make ferroelectric ceramic ball 1.

Be to prepare circular hole 3 arrays on the polyfluortetraethylene plate 2 of 1.0～3.0mm at thickness, the circular hole spacing is 1.0～3.0mm and is square profile, thereby obtains the polytetrafluoroethylene template.Ceramic cubic block or ball are embedded in the circular hole of polytetrafluoroethylene template, make two-dimentional ceramic cubic block or ball array.The polyfluortetraethylene plate circular hole aligning that will be embedded with ceramic cubic block or ball again carries out stacked bonding and obtains the three-dimensional ceramic array of particles.

At last with the three-dimensional ceramic cubic block or ball array is bonded together with two parallel metal electrodes 4 and be connected the electric field-tunable negative magnetic permeability part that promptly makes based on ferroelectric ceramic grain with high-voltage DC power supply, regulate the dielectric constant of ferroelectric ceramic grain by the size of regulating power electrical field, thereby realization electric field-tunable negative magnetic permeability, incident electromagnetic wave 5 is injected from the bottom of device, and outgoing electromagnetic wave 6 is penetrated by the top.

The performance of implementation procedure of the present invention and material is by embodiment and description of drawings:

Embodiment 1:

Adopt synthesis by solid state reaction to prepare Ba _0.5Sr _0.5TiO ₃(BST) powder.This method adopts highly purified BaCO ₃, SrCO ₃And TiO ₂Be raw material, react with following equation and make Ba _0.5Sr _0.5TiO ₃Powder.

0.5BaCO ₃+0.5SrCO ₃+TiO ₂＝Ba _0.5Sr _0.5TiO ₃+CO ₂↑

With BaCO ₃, SrCO ₃And TiO ₂Mix by above proportioning, through ball milling, dry, sieve after, 1150 ℃ of calcinings 3 hours, and then ball milling, that oven dry makes the BST powder was stand-by.

Utilize ceramic size curtain coating technology, BST powder and organic solvent are made into slurry carry out curtain coating, obtaining thickness is the 1.25mm cast sheet, then cast sheet is slit into cubic block that the length of side is 1.25mm and carries out binder removal at 300 ℃, at last 1350 ℃ of sintering 3 hours, obtain the length of side and be 1.0mm the ferroelectric ceramic cubic block.Its dielectric property with the variation relation curve of extra electric field as shown in Figure 2, as seen its relative dielectric constant under the room temperature null field is 2000.

Utilize Digit Control Machine Tool to get out the array of circular apertures of diameter for 1.42mm on the polyfluortetraethylene plate of thickness for 2.50mm, the circular hole spacing is 2.50mm and is square profile, thereby obtains the polytetrafluoroethylene template.Ceramic cubic block is embedded in the circular hole of polytetrafluoroethylene template, makes two-dimentional ceramic cubic block array.The polyfluortetraethylene plate circular hole aligning that will be embedded with ceramic cubic block again carries out stacked bonding and obtains three-dimensional ceramic cubic block array.

At last three-dimensional ceramic cubic block array is bonded together with two parallel metal copper electrodes and is connected the electric field-tunable negative magnetic permeability part that promptly makes based on ferroelectric ceramic grain with high-voltage DC power supply, regulate the dielectric constant of ferroelectric ceramic grain by the size of regulating power electrical field, thereby realize electric field-tunable negative magnetic permeability.Its electric field-tunable microwave transmission curve as shown in Figure 3.As seen from the figure, when electric field changes to 2.5kV/mm by 0, its corresponding magnetic resonance peak by the 5.5GHz blue shift to 9.0GHz.As seen corresponding magnetic permeability has realized the adjustable characteristic of magnetic permeability with the variation relation of electric field as shown in Figure 4.

Embodiment 2:

With embodiment one, utilize synthesis by solid state reaction to prepare Ba _0.5Sr _0.5TiO ₃(BST) powder, glue, sintering make the BST pottery cubic block of the length of side for 0.70mm side by side to utilize ceramic size curtain coating technology curtain coating.Its dielectric property with the variation relation curve of extra electric field as shown in Figure 2, as seen its relative dielectric constant under the room temperature null field is 2000.

Utilize Digit Control Machine Tool to get out the array of circular apertures of diameter for 1.00mm on the polyfluortetraethylene plate of thickness for 2.50mm, the circular hole spacing is 2.50mm and is square profile, thereby obtains the polytetrafluoroethylene template.Ceramic cubic block is embedded in the circular hole of polytetrafluoroethylene template, makes two-dimentional ceramic cubic block array.The polyfluortetraethylene plate circular hole aligning that will be embedded with ceramic cubic block again carries out stacked bonding and obtains three-dimensional ceramic cubic block array.

Three-dimensional ceramic cubic block array is bonded together with two parallel metal copper electrodes and is connected the electric field-tunable negative magnetic permeability part that promptly makes based on ferroelectric ceramic grain with high-voltage DC power supply, regulate the dielectric constant of ferroelectric ceramic grain by the size of regulating power electrical field, thereby realize electric field-tunable negative magnetic permeability.Its electric field-tunable microwave transmission curve as shown in Figure 5.As seen from the figure, when electric field changes to 2.5kV/mm by 0, its corresponding magnetic resonance peak by the 8.0GHz blue shift to 13.0GHz.

Embodiment 3:

With embodiment one, utilize synthesis by solid state reaction to prepare Ba _0.4Sr _0.6TiO ₃(BST) powder, the BST powder mixed with the 5wt%MgO powder and mix and be made into slurry and carry out curtain coating with organic solvent, make the cast sheet that thickness is 0.57mm, binder removal, sintering make the ceramic cubic block that the length of side is 0.45mm then, and the relative dielectric constant under the room temperature null field condition is 1600.

Utilize Digit Control Machine Tool to get out the array of circular apertures of diameter for 0.64mm on the polyfluortetraethylene plate of thickness for 1.00mm, the circular hole spacing is 1.00mm and is square profile, thereby obtains the polytetrafluoroethylene template.Ceramic cubic block is embedded in the circular hole of polytetrafluoroethylene template, makes two-dimentional ceramic cubic block array.The polyfluortetraethylene plate circular hole aligning that will be embedded with ceramic cubic block again carries out stacked bonding and obtains three-dimensional ceramic cubic block array.

At last three-dimensional ceramic cubic block array is bonded together with two parallel metal copper electrodes and is connected the electric field-tunable negative magnetic permeability part that promptly makes based on ferroelectric ceramic grain with high-voltage DC power supply.

Embodiment 4:

With embodiment one, utilize synthesis by solid state reaction to prepare Ba _0.6Sr _0.4TiO ₃(BST) powder, the BST powder mixed with the 20wt%MgO powder and mix and be made into slurry and carry out curtain coating with organic solvent, make the cast sheet that thickness is 2.30mm, binder removal, sintering make the ceramic cubic block that the length of side is 1.80mm then, and the relative dielectric constant under the room temperature null field condition is 600.

Utilize Digit Control Machine Tool to get out the array of circular apertures of diameter for 2.60mm on the polyfluortetraethylene plate of thickness for 3.00mm, the circular hole spacing is 3.00mm and is square profile, thereby obtains the polytetrafluoroethylene template.Ceramic cubic block is embedded in the circular hole of polytetrafluoroethylene template, makes two-dimentional ceramic cubic block array.The polyfluortetraethylene plate circular hole aligning that will be embedded with ceramic cubic block again carries out stacked bonding and obtains three-dimensional ceramic cubic block array.

Above-mentioned dielectric composite material sample is compound with two parallel metal aluminium electrodes and be connected the electric field-tunable negative magnetic permeability part that promptly makes based on ferroelectric ceramic grain with high-voltage DC power supply.

Embodiment 5:

With embodiment one, utilize synthesis by solid state reaction to prepare Ba _0.6Sr _0.4TiO ₃(BST) powder, the BST powder mixed with organic solvent be made into slurry and carry out curtain coating, make the cast sheet that thickness is 2.30mm, binder removal, sintering make the ceramic cubic block that the length of side is 1.80mm then, then it is worn into the Ceramic Balls that diameter is 1.0mm, the relative dielectric constant under the room temperature null field condition is 2000.

Utilize Digit Control Machine Tool to get out the array of circular apertures of diameter for 1.0mm on the polyfluortetraethylene plate of thickness for 2.50mm, the circular hole spacing is 2.50mm and is square profile, thereby obtains the polytetrafluoroethylene template.Ceramic Balls is embedded in the circular hole of polytetrafluoroethylene template, makes two-dimentional Ceramic Balls array.The polyfluortetraethylene plate circular hole aligning that will be embedded with Ceramic Balls again carries out stacked bonding and obtains the three-dimensional ceramic ball array.

Above-mentioned dielectric composite material sample is compound with two parallel silver electrodes and be connected the electric field-tunable negative magnetic permeability part that promptly makes based on ferroelectric ceramic grain with high-voltage DC power supply.

Claims (6)

1. electric field-tunable isotropism negative magnetic permeability part based on ferroelectric ceramic grain, it is characterized in that: described device is by two metal electrode boards that be arranged in parallel, be arranged on the stacked polyfluortetraethylene plate of polylith between two battery lead plates, ferroelectric ceramic grain and DC power supply are formed; Every polyfluortetraethylene plate is provided with array of circular apertures, and described ferroelectric ceramic grain embeds in each circular hole; This devices use electric field is realized the tunability of described isotropism negative magnetoconductivity to the regulating characteristics of ferroelectric ceramic grain dielectric constant.

2. according to the described electric field-tunable isotropism negative magnetic permeability part based on ferroelectric ceramic grain of claim 1, it is characterized in that: the relative dielectric constant of described ferroelectric ceramic grain is 600～2000.

3. according to the described electric field-tunable isotropism negative magnetic permeability part based on ferroelectric ceramic grain of claim 1, it is characterized in that: the array of circular apertures on the described polyfluortetraethylene plate is square profile and lattice constant is 1.0～3.0mm.

4. according to the described electric field-tunable isotropism negative magnetic permeability part based on ferroelectric ceramic grain of claim 3, it is characterized in that: it is the ferroelectric ceramic cubic block of 0.45～1.8mm or the ferroelectric ceramic ball that diameter is 0.5～2.6mm that described ferroelectric ceramic grain adopts the length of side.

5. the preparation method based on the electric field-tunable isotropism negative magnetic permeability part of ferroelectric ceramic grain is characterized in that this method comprises the steps:

1) utilize ceramic size curtain coating technology, with ferroelectric ceramic powder and MgO powder by mass percentage concentration 0～20% mix and be made into slurry and carry out curtain coating with organic solvent, obtain the cast sheet of different-thickness;

2) cast sheet is slit into cubic block that the length of side is 0.5～2.3mm and carry out binder removal at 300～500 ℃, at last 1300～1500 ℃ of sintering 3～6 hours, obtain the length of side and be the ferroelectric ceramic cubic block of 0.45～1.8mm or it is worn into the ferroelectric ceramic ball that diameter is 0.5～2.6mm;

3) prepare array of circular apertures on the thick polyfluortetraethylene plate of 1.0～3.0mm, circular hole is square profile and lattice constant is 1.0～3.0mm; Ceramic cubic block or Ceramic Balls are embedded in each circular hole of polyfluortetraethylene plate, make two-dimentional ceramic particle array;

4) the polyfluortetraethylene plate circular hole aligning that will be embedded with ceramic particle again carries out stacked bonding, obtains the three-dimensional ceramic array of particles; At last three-dimensional ceramic array of particles and two metal electrode boards that be arranged in parallel are bonded together;

5) regulate the dielectric constant of ferroelectric ceramic grain by the size of regulating power electrical field, thereby obtain electric field-tunable isotropism negative magnetic permeability part.

6. according to the preparation method of the described electric field-tunable isotropism negative magnetic permeability part based on ferroelectric ceramic grain of claim 5, it is characterized in that: described ferroelectric ceramic powder adopts Ba _xSr _1-xTiO ₃Powder, wherein x is 0.4～0.6.

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