Magnetoresistance of GaPAs and InSb whiskers

The magnetoresistance of GaP x As 1− x ( x = 0.4) whiskers with a doping concentration of silicon in the range from the dielectric side of metal-insulated transition (MIT) (~ 10 17 cm −3 ) to its critical concentration ( N c ~ 5 × 10 18 cm −3 ) at cryogenic temperatures of 4.2–77 K and magnetic field induction of 0–14 T was studied. A negative magnetic resistance (NMR) with a maximum value of 7% was found at a temperature of 4.2 K and a magnetic field of 4.5 T, which is dependent on magnetic field induction and current direction. The NMR absolute value reduces with increasing temperature was observed in the transverse and longitudinal magnetoresistance. The nature of the revealed NMR effect was discussed in the studied samples. A similar effect was observed in InSb whiskers. There are four possible reasons for the NMR effect in the GaP x As 1− x and InSb whiskers such as dimensional quantization, the magnetic ordering of electron spins or magnetic ordering due to uncontrolled magnetic dopant introduction and quantum interference of the electron wave function. The GaP x As 1− x whisker application as the temperature sensor was proposed due to the studied results of the temperature dependence of their conductivity.