LOW-TEMPERATURE MAGNETORESISTANCE EFFECT AND THERMOELECTRIC PROPERTIES OF POLYCRYSTALLINE FeAs2 THIN FILM ON LaAlO3 (100) SUBSTRATE

Abstract

The polycrystalline FeAs2 thin film grown on a LaAlO3
(100) substrate by using
molecular beam epitaxy (MBE) has been investigated. The origin of negative
magnetoresistance (MR) is observed at 20K due to hopping conduction mechanism.
The films exhibit semiconductor behavior with dominant charge-carrier being
electron. Above room temperature, the electrical activation energy is estimated to
be 0.20eV, that original from transport mechanism such as thermionic emission. The
maximal Seebeck coefficient is, S = -138μV/K at T = 300K.