Excess Specific Heat in the Anderson Localized States Observed in the 1T-Ta_1−xTi_xS₂ System

Abstract

The specific heat of 1T-Ta_1−xTi_xS₂ in the concentration range of 0≤x≤0.144 was measured from 1.5 to 5 K. The specific heat in magnetic field up to 60 kOe was also measured for two samples with x=0.04 and 0.07. Excess specific heat was observed at low temperatures for all the samples studied. It was also found that the excess specific heat depends on the magnetic field for the metallic (x=0.04) samples as well as for the nonmetallic (x=0.07) one. Excess specific heat analyzed as a Schottky type one is confirmed to be related to the Anderson localized states. The results are discussed by considering not only the intrastate electron correlation but also the interstate one between Anderson localized states.