Synthesis of low-moment CrVTiAl: A potential room temperature spin filter

The efficient production of spin-polarized currents at room temperature is fundamental to the advancement of spintronics. Spin-filter materials—semiconductors with unequal band gaps for each spin channel—can generate spin-polarized current without the need for spin-polarized contacts. In addition, a spin-filter material with zero magnetic moment would have the advantage of not producing strong fringing fields that would interfere with neighboring electronic components and limit the volume density of devices. The quaternary Heusler compound CrVTiAl has been predicted to be a zero-moment spin-filter material with a Curie temperature in excess of 1000 K. In this work, CrVTiAl has been synthesized with a lattice constant of a = 6.15 A. Magnetization measurements reveal an exceptionally low moment of μ = 2.3 × 10−3 μB/f.u. at a field of μ0H = 2 T that is independent of temperature between T = 10 K and 400 K, consistent with the predicted zero-moment ferrimagnetism. Transport measurements reveal a combination o...