Evidence for ferromagnetic ordering in the MAX phase (Cr0.96Mn0.04)2GeC

Abstract

Magnetic ordering in the MAX phase (Cr0.96Mn0.04)2GeC is investigated by means of neutron powder diffraction (NPD). Upon cooling, the temperature dependence of the magnetization shows a two-step increase. The NPD refinement reveals that the first step, at 300 K, and the second step, at 38 K, originate from a collinear magnetic structure within the MAX phase and a spinel MnCr2O4 impurity phase, respectively. The former magnetic structure is oriented perpendicular to the c axis, with a net magnetic moment of ∼0.6(2) μB per Cr/Mn atom at 50 K. This is the first direct evidence for magnetic ordering within a bulk MAX phase.

Keywords

• MAX phase
• neutron powder diffraction
• magnetic ordering
• transition metals magnetism