CN2591723Y

CN2591723Y - Nail punching thin film with laminated ferro magnetic layer

Info

Publication number: CN2591723Y
Application number: CN 02293463
Authority: CN
Inventors: 代波; 蔡建旺; 赖武彦
Original assignee: Institute of Physics of CAS
Current assignee: Institute of Physics of CAS
Priority date: 2002-12-24
Filing date: 2002-12-24
Publication date: 2003-12-10
Anticipated expiration: 2012-12-24

Abstract

The utility model relates to a pinning thin film with a laminated ferromagnetic layer. The pinning thin film comprises a substrate made of silicon or glass, a buffer layer, a second ferromagnetic layer and a protecting layer, wherein the buffer layer and the second ferromagnetic layer are arranged on the substrate and are made of Ta or (Ni#-< X > Fe#-< 100-X >) #-< y > Cr#-< 100-Y >, wherein X is more than 77 and smaller than 83, Y is more than 50 and smaller than 70; the protecting layer is arranged on the second ferromagnetic layer and prevents the surface of the second ferromagnetic layer from oxidizing. The utility model also comprises a guide layer, an antiferromagnetic layer, a first ferromagnetic layer and a nanometer oxidizing layer, wherein the guide layer which induces the antiferromagnetic layer to form (111) texture is arranged on the buffer layer and is provided with the (111) texture; the antiferromagnetic layer which is made of manganese alloy is arranged on the guide layer and is provided with the (111) texture, and the percentage composition of Mn atoms in the manganese alloy is 55 percents to 70 percents; the first ferromagnetic layer which is arranged on the antiferromagnetic layer is made of Ni, Ni#-< X > Fe#-< 100-X >, or Co#-< Y > Fe#-< 100-Y >, wherein X is more than 77 and smaller than 83, and Y is more than 87 and smaller than 93; the nanometer oxidizing layer which is oxidated by the first ferromagnetic layer is arranged between the first ferromagnetic layer and the second ferromagnetic layer. The thickness of the antiferromagnetic layer of the pinning thin film of the utility model is obvious reduced, and a pinning field is larger. The utility model also realizes the pinning of Ni-Mn to Co-Fe.

Description

Pinning film with laminated iron magnetosphere

Technical field

The utility model relates to a kind of magnetic material that is applied to Spin Valve, MTJ, transducer etc., and the film of the pinning with laminated iron magnetosphere is provided especially.

Background technology

Aspect the ferromagnetic/antiferromagnetic pinning film of preparation, show by prior art: Mn alloy with face-centred cubic structure, (wherein X is another element to the antiferromagnetic X-Mn of the annealed center of area tetragonal that changes atomic ordered into, Ni, Pt and Pd etc.) ferromagnetic/antiferromagnetic multilayer film pinning film of being formed, generally all has bigger pinning field, and good resistance to corrosion and thermal stability, so obtain to use widely at aspects such as transducers.Fig. 1 be known ferromagnetic/structure of antiferromagnetic multilayer film pinning film, its each layer is followed successively by: substrate 1, resilient coating 2, ferromagnetic layer 70, inverse ferric magnetosphere 4, and protective layer 8.But, because known this ferromagnetic/antiferromagnetic multilayer film pinning film, in preparation process, required annealing time all very long (tens hours), or its annealing temperature very high (more than 300 ℃), therefore diffusive migration takes place in the Mn in the inverse ferric magnetosphere 4 in the annealing process, enter adjacent ferromagnetic layer 70, thereby cause the loss of ferromagnetic layer 70 magnetic moments, coercitive increase and magnetic hysteresis loop rectangle degree variation, and the inverse ferric magnetosphere in this material 4 is general thicker, more than 250 , the pinning field of 4 pairs of ferromagnetic layers 70 of inverse ferric magnetosphere of this material is not ideal, and the pinning field is generally about 200 oersteds.By as seen above-mentioned, prevent Mn in the annealing process to ferromagnetic layer diffusion and attenuate inverse ferric magnetosphere be acquisition high performance ferromagnetic/key point of antiferromagnetic multilayer film pinning film, also be a difficult problem to be solved.

Be pointed out that, because behind the annealing process of this multilayer film pinning film in preparation process, a little variation can take place structure, so in the present technique field, usually discuss qualitatively and compare with the preceding multi-layer film structure of annealing.Therefore, all multi-layer film structures of mentioning hereinafter and each layer corresponding thickness except that particularly pointing out, all are as the criterion with the state before annealing.

Document (T.Lin, C.Tsang, R.E.Fontana and J.K.Howard, IEEE Trans.Magn., 31 (1995), 2585.) disclosed the variation of the pinning field of ferromagnetic layer Ni-Fe of inverse ferric magnetosphere Ni-Mn pinning 150 of 300 and coercive force with annealing time and annealing temperature, promptly will produce reasonable pinning effect, or annealing temperature is than higher (such as 320 ℃, 5 hours), annealing time long (such as 280 ℃, 20 hours)

Document (M.Lederman, IEEE Trans.Magn., 35 (1999), 794) has disclosed the relation of pinning field and coercive force and Ni-Mn thickness, and this document points out that Ni-Mn thickness must be greater than 300 ; Afterwards, also there was investigation of materials person to prepare the Ni-Mn inverse ferric magnetosphere of 250 , so we think that the thickness of the Ni-Mn that mentions on the document is basically all greater than 200 .

In addition, because the direct pinning Co-Fe of Ni-Mn,, but do not obtain effect preferably so former to have the people once to attempt with the Ni-Mn alloy be the pinning of inverse ferric magnetosphere realization to Co-Fe.

Therefore, how under lower annealing temperature and shorter annealing time, acquisition is the multilayer film pinning film of alloy as inverse ferric magnetosphere pinning Co-Fe ferromagnetic layer with Mn, and has thinner inverse ferric magnetosphere, bigger pinning field, is one of the important topic in preparation pinning film field.

Summary of the invention

The purpose of this utility model is in order to reduce inverse ferric magnetosphere thickness, shorten annealing time or to reduce annealing temperature, and prevent that Mn spreads to ferromagnetic layer in the annealing process, realize the better pinning of inverse ferric magnetosphere, thereby the film of the pinning with laminated iron magnetosphere is provided ferromagnetic layer.

The purpose of this utility model can realize by following measure:

Pinning film with laminated iron magnetosphere, comprise a substrate of making by silicon or glass and on substrate, be provided with one by Ta or (Ni _XFe _100-X) _YCr _100-Y, wherein resilient coating, one second ferromagnetic layer made of 77＜X＜83,50＜Y＜70 and establish thereon a protective layer that prevents the second ferromagnetic layer surface oxidation is characterized in that, also comprises:

One induces inverse ferric magnetosphere to form the guide layer of (111) texture, is located on the resilient coating, and this guide layer has (111) texture;

One is the inverse ferric magnetosphere that 55% to 70% manganese alloy is made by the Mn atomic percentage conc, is located on the guide layer, and this inverse ferric magnetosphere has (111) texture;

One by Ni, Ni _XFe _100-X, or Co _YFe _100-Y, wherein first ferromagnetic layer made of 77＜X＜83,87＜Y＜93 is located on the inverse ferric magnetosphere; And

One nano-oxide layer that is formed by this first ferromagnetic layer oxidation is located between first ferromagnetic layer and second ferromagnetic layer.

Described inverse ferric magnetosphere thickness is 100 to 200 .

Described nano-oxide layer, thickness are 10 to 20 .

The utility model has following advantage compared to existing technology:

The pinning film that the utility model provides with laminated iron magnetosphere, atomic percentage conc by the Mn of control in the inverse ferric magnetosphere and adopt first ferromagnetic layer, nano-oxide layer and guide layer, thereby make the obvious attenuate of inverse ferric magnetosphere thickness, its pinning field is bigger, coercive force is littler, magnetic hysteresis loop rectangle degree is better, as shown in Figure 3; Almost there is not the diffusion of Mn in this second ferromagnetic layer; And realized the pinning of Ni-Mn to Co-Fe.

Description of drawings

Fig. 1 be known ferromagnetic/structure of antiferromagnetic multilayer film pinning film;

Fig. 2 is the structure with pinning film of laminated iron magnetosphere of the present utility model; And

Fig. 3 is the magnetic hysteresis loop of the finished product of embodiment one of the present utility model.

Drawing explanation: 1-substrate; The 2-resilient coating; The 3-guide layer; The 4-inverse ferric magnetosphere; 5-first ferromagnetic layer; The 6-nano-oxide layer; 7-second ferromagnetic layer; The 8-protective layer; The 70-ferromagnetic layer.

Embodiment

See also Fig. 2, be the structure with pinning film of laminated iron magnetosphere of the present utility model.The structure of this material is the protective layer to the other end 8 from substrate 1, and each layer is followed successively by resilient coating 2, guide layer 3, inverse ferric magnetosphere 4, first ferromagnetic layer 5, nano-oxide layer 6, second ferromagnetic layer 7 therebetween.

Embodiment one:

See also Fig. 2.The structure of the pinning film with laminated iron magnetosphere in this embodiment forms as follows: at first adopt vacuum deposition method, the first ferromagnetic layer Ni5, the thickness that plate thickness successively and be the resilient coating Ta2 of 30 , guide layer Ni3 that thickness is 20 , inverse ferric magnetosphere Ni-Mn4, thickness that thickness is 150 on Si substrate 1 and be 30 are the second ferromagnetic layer Co of 60 ₉₀Fe ₁₀7, thickness is the protective layer Ta8 of 30 ; Wherein in plating bianry alloy Ni-Mn inverse ferric magnetosphere 4 processes, making the atomic percentage conc of element M n in this layer is 70%; Plated thick be the first ferromagnetic layer Ni of 30 after, with the industrial pure oxygen of autoxidation or plasma oxidation mode or 0.5Pa to sample surfaces oxidation 10 minutes, thereby at the first ferromagnetic layer Ni and the second ferromagnetic layer Co ₉₀Fe ₁₀The interface on form one deck nano-oxide layer 6 (NOL), thickness is about 10 -20 .Then, with sample place direction be parallel to sample easily axle externally-applied magnetic field under, magnetic field intensity is for being about 10 ²Oersted, and the base vacuum degree is less than 10 ^-2Pa is 280 ℃ through excess temperature, annealing in 5 hours.Because the existence of nano-oxide layer 6 (NOL), when annealing, blocked the diffusion of Mn to second ferromagnetic layer 7, when Mn below three interlayers (Ni/Ni-Mn/Ni) spread when mobile, can form the inverse ferric magnetosphere 4 of the Ni-Mn of the ordered phase that waits atomic ratio more uniformly, thereby realize the second ferromagnetic layer CoXFe ₁₀7 pinning.Because the atomic percentage conc of the preceding Mn of inverse ferric magnetosphere Ni-Mn 4 annealing in the system is higher to be 70%, the Mn atom moves easily during annealing, thereby annealing time can be shorter, NOL has blocked the diffusion of Mn towards second ferromagnetic layer 7, make to have formed uniform Ni-Mn ordered phase in following three layers, promptly among the inverse ferric magnetosphere Ni-Mn4 of annealing back the atomic percentage conc of element M n for being about 50%.Nano-oxide layer 6 (NOL) may also be magnetic, and it is in the inverse ferric magnetosphere Ni-Mn4 and the second ferromagnetic layer Co ₉₀Fe ₁₀7 interface, thus realized that inverse ferric magnetosphere Ni-Mn4 is to the second ferromagnetic layer Co ₉₀Fe ₁₀7 pinning, and measure proof, this material magnetic hysteresis loop through vibrating specimen magnetometer as shown in Figure 3, its coercive force is about 60 oersteds, the coercive force of the material that this coercive force and annealing are preceding is identical, the pinning field is 310 oersteds, loop line rectangle degree is fine.

Embodiment two:

See also Fig. 2.The structure of the pinning film with laminated iron magnetosphere in this embodiment is: the thickness from substrate Si1 to the other end is the protective layer Ta8 of 30 , and to be followed successively by resilient coating Ta2, thickness that thickness is 30 be the guide layer Ni of 30 to each layer therebetween ₈₀Fe ₂₀3, thickness is that inverse ferric magnetosphere Pt-Mn4, the thickness of 100 are the first ferromagnetic layer Co of 15 ₉₀Fe ₁₀5 and thickness be the nano-oxide layer 6 of 15 and the second ferromagnetic layer Co that thickness is 100 ₉₀Fe ₁₀7.The shared atomic percentage conc of element M n is 55% before the above-mentioned inverse ferric magnetosphere Pt-Mn annealing, is about 50% after the annealing.

Embodiment three:

See also Fig. 2.The structure of the pinning film with laminated iron magnetosphere in this embodiment is: the thickness from substrate glass 1 to the other end is the protective layer Ta8 of 30 , and each layer is followed successively by the resilient coating (Ni that thickness is 30 therebetween ₈₀Fe ₂₀) ₆₀Cr ₄₀2, thickness is the guide layer Ni of 30 ₈₀Fe ₂₀3, thickness is that inverse ferric magnetosphere Pd-Mn4, the thickness of 200 are the first ferromagnetic layer Ni of 520 ₈₀Fe ₂₀5 and thickness be the nano-oxide layer 6 of 15 and the second ferromagnetic layer Co that thickness is 100 ₉₀Fe ₁₀7.The shared atomic percentage conc of element M n is 60% before the above-mentioned inverse ferric magnetosphere Pd-Mn annealing, is about 50% after the annealing.

Claims

1, the pinning film that has the laminated iron magnetosphere, comprise a substrate of making by silicon or glass and on substrate, be provided with one by Ta or (Ni _XFe _100-X) _YCr _100-Y, wherein resilient coating, one second ferromagnetic layer made of 77＜X＜83,50＜Y＜70 and establish thereon a protective layer that prevents the second ferromagnetic layer surface oxidation is characterized in that, also comprises:

2, the pinning film with laminated iron magnetosphere as claimed in claim 1 is characterized in that, this inverse ferric magnetosphere thickness is 100 to 200 .

3, the pinning film with laminated iron magnetosphere as claimed in claim 1 is characterized in that, described nano-oxide layer, thickness are 10 to 20 .