Magnetoresistance Sensitivity Research Articles

Characteristics of Highly Sensitive Magnetoresistive Sensors

A barber-pole type magnetoresistive sensor with excellent sensitivity and temperature characteristics is described. 76 wt% Ni-Fe layers 480 A and 1030 A thick were vapor deposited with a TaMo adhesive layer and Au patterning; magnetic field annealing was used to induce uniaxial anisotropy. Output characteristics were reproducible to within 1 percent, with minimal hysteresis effects; the average sensitivity was 0.13 mV/Oe·mA, comparable to that of InSb Hall sensors, while the output temperature coefficient was -0.09 %/°C, superior to InSb devices. The test device was used to read data from a magnetic card, with good results.

Fabrication of high sensitivity thin-film indium antimonide magnetoresistors

A method is described for fabricating high-sensitivity thin film of InSb. The fabrication procedure consists of the sequential deposition of chromium, antimony and indium. The films are then heat treated to thermo-chemically produce polycrystalline InSb films. The free-electron mobility of these films is found to be 5.4 × 10 4 cm 2/V. sec, and the free carrier density to be 10 16 cm −3. Magnetoresistors were fabricated from these films with addition of indium, Hall-voltage shorting strips. The magnetoresistance sensitivity of these resistors was found to be 45 per cent K G, which compares very favourably with that obtained from single crystal InSb resistors.

Cd3As2 Thin Film Magnetoresistor

A magnetoresistor is fabricated by using a thin film of n-type Cd3As2. The Hall mobility is constant below 200°K in most of thin films, and in some films below 300°K. The geometry of a device has an important effect on the magnetoresistance. The resistance of this magnetoresistor at zero magnetic field is 190Ω. The magnetoresistance changes according to B2 up to 1 Wb/m2. The resistance change of 4Ω is obtained at 0.5 Wb/m2. The magnetoresistance sensitivity is 0.7 m4Ω/Wb2. The Cd3As2 thin film magnetoresistor has the following advantages: 1) it can be easily prepared by the usual evaporation method; 2) this device has no temperature dependence below 200°K in most cases, and in some cases below room temperature.

Some peculiarities of the electron-excited conduction in dielectrics.

The possibility of using binary amorphous Co1 − xZrx thin film alloys as ultrasoft thin films in spin valve Co1 − xZrxCuCo structures is shown. The effect of zirconium content, thicknesses of Co1 − xZrx and spacer Cu layers and sputtering deposition pressure was investigated. In the optimal sputtering conditions for a spin valve sample of Co0.98Zr0.02 (3 nm)Cu(2 nm)Co(2 nm), the sensitivity of magneto-resistance was found to be (around) 2% per Oersted.