CN1069435C - Granular membrane huge magnetic resistance effect sensor material - Google Patents

Abstract

A magnetic sensor material, characterized in that it adopts magnetron sputtering, ion beam sputtering, quick quenching and other processes to embed ferromagnetic particles in a non-magnetic medium that is incompatible with solid solution, and forms a non-uniform phase composition system. Its chemical The general formula is: FxA(1-x) where F represents Fe, Ni, Co, Mn, FeSi, FeCo, FeNi, MnAl, MnBi and other ferromagnetic metals and their alloys. A represents Au, Ag, Cu and other metals that are insoluble with Fe, Ni, Co, and insulators such as SiO ₂ , Al ₂ O ₃ , BN, and semiconductor elements such as Si and Ge. X is the volume percentage, and X is 10 <X<50%. The present invention is characterized in that it adopts sputtering and rapid quenching process to generate particle film at one time, and the process is simple for many layers of film, with high yield and low price.

Description

Granular film giant magnetoresistance effect sensor material

The invention relates to a metal-metal, metal-insulator (including semiconductor) magnetic granular film giant magnetoresistance material and its technology.

At present, most of the sensors for detecting magnetic fields use the Hall effect. The disadvantage is that the semiconductor Hall element is easily damaged, has directionality during measurement, and the sensitivity is not high enough. In the late 1980s, FeNi and other magnetic alloy films with anisotropic magnetoresistance effect began to be developed as magnetic sensors. In 1988, people first found a much larger negative magnetoresistance effect than FeNi alloy in multilayer films such as Fe/Cr and Co/Cu, which is called the giant resistance effect. In 1992, it was reported that Co-Cu granular films also existed Isotropic giant magnetoresistance effect. The discovery of this effect provides a new type of artificial functional material for magnetic sensors. Its resistivity is about 10 ^-5 -10 ^-6 Ωcm. In order to be practical, photolithography is usually required. to increase the resistance value.

The solution of the present invention is: use magnetron sputtering, ion beam sputtering, quick quenching and other processes to embed ferromagnetic particles in non-magnetic media with immiscible solid solution to form a heterogeneous phase composition system, and its general chemical formula For: FxA (1-x) where F represents Fe, Ni, Co, Mn, FeSi, FeCo, FeNi, MnAl, MnBi and other ferromagnetic metals and their alloys. A represents Au, Ag, Cu and other metals that are insoluble with Fe, Ni, Co, and insulators such as SiO ₂ , Al ₂ O ₃ , BN, and semiconductor elements such as Si and Ge. X is the volume percentage, and X is 10 <X<50%.

The present invention is characterized in that it adopts sputtering and rapid quenching process to generate particle film at one time, and the process is simple for many layers of film, with high yield and low price.

The magnetic metal-insulator particle film adopted in the invention has the advantages of convenient preparation, good repeatability, high chemical stability and high resistance value, and can be a new functional material of a magnetic sensor. Below in conjunction with accompanying drawing and by embodiment the present invention will be further described:

Figure 1 is the relationship between the room temperature giant magnetoresistivity Δρ/ρ and the external magnetic field of the CoAg granular film

Figure 2 is the relationship between the room temperature giant magnetoresistivity Δρ/ρ and the external magnetic field of the CoCu granular film

Figure 3 is the relationship between the room temperature giant magnetoresistivity Δρ/ρ and the external magnetic field of the CoNiCu granular film

Figure 4 is the relationship between the room temperature giant magnetoresistivity Δρ/ρ and the external magnetic field of the _FeSiO2 granular film

Example 1. Co ₂₂ Ag ₇₈ particle film, using ion beam co-sputtering process, Co-Ag composite target, vacuum degree -10 ^-4 Pa, substrate is cover glass or Al ₂ O ₃ ceramic sheet, sputtering After film formation, vacuum treatment at 500K for half an hour, the room temperature giant magnetoresistivity Δρ/ρ. The relationship curve with the external magnetic field is shown in Figure 1.

Example 2. Co ₂₀ Cu ₈₀ particle film, using DC magnetron sputtering process, the vacuum degree is 10 ^-3 Pa, the working gas Ar (99.99%) pressure is 0.8 Pa, the substrate is a cover glass or Si (100) single Wafer, vacuum heat treatment at 400°C after sputtering film formation, ion beam co-sputtering also obtained similar results, room temperature giant magnetoresistivity Δρ/ρ. The relationship curve with the external magnetic field is shown in Figure 2.

Example 3. Co ₁₅ Ni ₁₀ Cu ₇₅ granular film, the preparation process is as in Example 2, and the giant magnetoresistivity Δρ/ρo has a better reversible and linear relationship with the external magnetic field within the measured magnetic field range. See Figure 3. The material has a phase structure characteristic of destabilizing decomposition.

Example 4. Fe ₂₈ SiO ₇₂ particle film, using ion beam sputtering process, Fe-SiO2 composite target, experimental conditions as in example 1, room temperature Δρ/ρ-H see graph 4.

Claims (2)

1. A magnetic sensor material, in which ferromagnetic particles are embedded in a non-magnetic medium with no phase solid solution, magnetron sputtering and ion beam measurement technology are used to form a heterogeneous phase composition system, and its general chemical formula is: FxA(1-x) where F represents ferromagnetic metals such as Fe, Ni, Co and their alloys, A represents SiO ₂ , X is volume percentage, and X is 10<X<50%. 2. The FxA(1-x) granular film material according to claim 1, characterized in that the composition ratio is Fe ₂₈ SiO ₂₇₂ .

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