Temperature and magnetic field induced structural transformation in Si doped CeFe2: in-field x-ray diffraction study

TL;DR

This study investigates how temperature and magnetic fields induce structural changes in Si-doped CeFe2 using in-field x-ray diffraction, revealing phase transitions, metastability, and lattice effects influencing magnetization.

Contribution

It provides a detailed quantitative analysis of the magnetostructural phase transitions and the role of lattice distortion in Si-doped CeFe2, highlighting the importance of lattice-spin coupling.

Findings

Identification of first order phase transition features

Observation of lattice volume mismatch causing magnetization steps

Explicit treatment of lattice distortion improves understanding of magnetization behavior

Abstract

Using x-ray powder diffraction technique at various temperatures and applied magnetic fields, we have studied the magnetostructural properties of Ce(Fe0.95Si0.05)2. The x-ray diffraction data establish quantitative relationships between bulk magnetization and the evolution of structurally distinct phases with magnetic field and temperature, and confirm the distinct features of first order phase transition like supercooling and superheating, metastability, and phase co-existence of different structural polymorphs. We observe the lattice volume mismatch across the structural phase transition, which appears to be the cause for the step behavior of the magnetization isotherms at low temperatures. The present study shows that the lattice distortion has to be treated explicitly, like spin, along with the effects of lattice-spin coupling to account for the magnetization behavior of this system. This structure template can resolve the issue of kinetics in this material as observed in different time scale measurements and with different experimental protocols.