The antiferromagnetic to ferrimagnetic phase transition in Mn&lt;sub&gt;2&lt;/sub&gt;Sb&lt;sub&gt;1-x&lt;/sub&gt;Bi&lt;sub&gt;x&lt;/sub&gt; compounds

Shen, Q.; Batashev, I.; Zhang, F.; Ojiyed, Hamutu; van Dijk, N.H.; Brück, E.H.

doi:10.1016/j.jallcom.2021.158963

The antiferromagnetic to ferrimagnetic phase transition in Mn₂Sb_1-xBi_x compounds

Title

The antiferromagnetic to ferrimagnetic phase transition in Mn₂Sb_1-xBi_x compounds

Author

Shen, Q. (TU Delft RST/Fundamental Aspects of Materials and Energy)
Batashev, I. (TU Delft RST/Fundamental Aspects of Materials and Energy)
Zhang, F. (TU Delft RST/Fundamental Aspects of Materials and Energy)
Ojiyed, Hamutu (External organisation)
van Dijk, N.H. (TU Delft RST/Fundamental Aspects of Materials and Energy)
Brück, E.H. (TU Delft RST/Fundamental Aspects of Materials and Energy)

Date

2021

Abstract

The influence of partial substitution of Bi for Sb on the structure, magnetic properties and magnetocaloric effect of Mn₂Sb_1-xBi_x (x = 0, 0.02, 0.04, 0.05, 0.07, 0.09, 0.15, 0.20) compounds has been investigated. The transition temperature of the antiferro-to-ferrimagnetic (AFM-FIM) transition initially increases with increasing Bi and decreases above 9%. Density functional theory calculations indicate that the Bi atoms prefer to occupy only the Sb site, which accounts for the large magnetization jump in Mn₂Sb_0.93Bi_0.07. As large lattice parameters are found for Bi substituted Mn₂Sb, the origin of the AFM-FIM transition in Mn₂Sb_(1-x)Bi_x compounds is ascribed to an enhanced coefficient of thermal expansion along the c axis, resulting from the Bi substitution. The moderate entropy change of 1.17 J/kg K under 2 T originating from the inverse magnetocaloric effect and the strong magnetic field dependence of the transition temperature of dT_t/dµ₀H = −5.4 K/T in Mn₂Sb_0.95Bi_0.05 indicate that this alloy is a promising candidate material for magnetocaloric applications.