The magnetic interactions in spin-glasslike Ge/1-x-y/Sn/x/Mn/y/Te diluted magnetic semiconductor

TL;DR

This study explores the complex magnetic phase transitions in Ge/Sn/Mn/Te diluted magnetic semiconductors, revealing coexistence of spin-glass and ferromagnetic behaviors below 50 K through experimental and theoretical analysis.

Contribution

It introduces a comprehensive analysis combining experimental magnetization data with theoretical models to understand magnetic phases in Ge/Sn/Mn/Te semiconductors, highlighting the presence of spin-glass and ferromagnetic states.

Findings

Magnetic ordering below 50 K shows spin-glass and ferromagnetic features.

Spin-glass state is favored at certain carrier concentrations and Mn content.

Theoretical models accurately reproduce magnetization behavior.

Abstract

We investigated the nature of the magnetic phase transition in the Ge/1-x-y/Sn/x/Mn/y/Te mixed crystals with chemical composition changing in the range of 0.083 < x < 0.142 and 0.012 < y < 0.119. The DC magnetization measurements performed in the magnetic field up to 90 kOe and temperature range 2-200 K showed that the magnetic ordering at temperatures below T = 50 K exhibits features characteristic for both spin-glass and ferromagnetic phases. The modified Sherrington - Southern model was applied to explain the observed transition temperatures. The calculations showed that the spin-glass state is preferred in the range of the experimental carrier concentrations and Mn content. The value of the Mn hole exchange integral was estimated to be J/pd/ = 0.45+/-0.05 eV. The experimental magnetization vs temperature curves were reproduced satisfactory using the non-interacting spin-wave theory with the exchange constant J/pd/ values consistent with those calculated using modified Sherrington - Southern model. The magnetization vs magnetic field curves showed nonsaturating behavior at magnetic fields B < 90 kOe indicating the presence of strong magnetic frustration in the system. The experimental results were reproduced theoretically with good accuracy using the molecular field approximation-based model of a disordered ferromagnet with long-range RKKY interaction.