New room-temperature ferromagnet: B-added Pd0.75Mn0.25 alloy

TL;DR

This study demonstrates that adding boron to Pd0.75Mn0.25 alloy induces room-temperature soft ferromagnetism, with magnetic properties tunable by boron concentration, transforming it from a spin-glass to a ferromagnet.

Contribution

It reveals that boron addition can induce and control room-temperature ferromagnetism in Mn-based alloys, a novel chemical tuning method.

Findings

Maximum Curie temperature of 390 K at x=0.125

Saturated Mn moment increases to 2.68μB/Mn with boron addition

Ferromagnetism is tunable solely by boron concentration

Abstract

Mn-based room-temperature ferromagnets attract considerable attention due to their high ordered Mn moment. We have found that a Pd0.75Mn0.25 alloy with added B (Pd0.75Mn0.25Bx) shows room-temperature soft ferromagnetism, whereas the parent Pd0.75Mn0.25 alloy is a spin-glass system. The saturated Mn moment at room temperature systematically increases to 2.68\muB/Mn as x increases to 0.125. The maximum Curie temperature of 390 K is also realized at an x of 0.125. The experimental results suggest a tunable soft ferromagnetism, which is governed only by the boron concentration. Our results will pave the way in chemical control of room-temperature bulk ferromagnetism in Mn compounds based on the addition of an atom with a small atomic radius.