We have investigated the field direction dependence of thermo-magnetic behavior in single crystalline Mn5Ge3. The adiabatic temperature change ΔTad in pulsed fields, the isothermal entropy change ΔSiso calculated from static magnetization measurements, and heat capacity have been determined for fields parallel and perpendicular to the easy magnetic direction [001]. The isothermal magnetization measurements yield, furthermore, the uniaxial anisotropy constants in second and fourth order, K1 and K2. We discuss how the anisotropy affects the magneto-caloric effect (MCE) and compare the results to the related compound MnFe4Si3, which features an enhanced MCE, too, but instead exhibits strong easy plane anisotropy. Our study reveals the importance of magnetic anisotropy and opens new approaches for optimizing the performance of magnetocaloric materials in applications.

High-pressure devices used in neutron scattering require materials with high strength, low neutron attenuation, and no activation. They should also be non-magnetic. Only very few materials fulfil these criteria. Here, it is reported on the manufacture and properties of the Ni–Cr–Al alloy (57.0 wt-% Ni, 40.0 wt-% Cr, and 3.0 wt-% Al). The casting and heat treatment to obtain the material with the optimal yield strength are described in detail. Synchrotron powder diffraction reveals that phases of the Ni2Cr, Cr, and Ni3Al types are present. Aging has no significant effect on their lattice parameters and volume fractions. The alloy has no magnetic order down to at least 1.9 K as evidenced by magnetic measurements and diffraction with polarised neutrons. This paper is part of a Thematic Issue on The Crystallographic Aspects of Metallic Alloys.

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