Magnetic contribution to the specific heat of Pb_{1-x}Eu_{x}Te

TL;DR

This study investigates the magnetic specific heat of Pb_{1-x}Eu_{x}Te at low temperatures, revealing a maximum influenced by magnetic fields, and proposes a model with split ground states of europium ions to explain the data.

Contribution

The paper introduces a model accounting for ground state splitting of europium ions to explain magnetic specific heat behavior in Pb_{1-x}Eu_{x}Te.

Findings

Maximum in magnetic specific heat between 1 and 3 K

Shift of the maximum to higher temperatures with increasing magnetic field

Ground state splitting of europium ions supported as a key factor

Abstract

The temperature dependence of the magnetic specific heat has been studied experimentally and theoretically in the semimagnetic semiconductor Pb_{1-x}Eu_{x}Te for x=0.027 and x=0.073, over the temperature range from 0.5 K to 10 K, in magnetic fields up to 2 T. There was a maximum in the magnetic specific heat between 1 and 3 K even in zero and low magnetic fields; this maximum shifted toward higher temperatures with increasing magnetic field. The experimental data have been analyzed in the framework of a model in which we assume that the ground states of europium ions are split even without an external magnetic field. We present arguments which support this assumption and we show that it is possible to find a physical mechanism leading to the splitting which can explain the experimental results.