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

TL;DR

This paper reports the synthesis and characterization of CrVTiAl, a low-moment, zero-magnetic-moment Heusler compound, demonstrating its potential as a room-temperature spin-filter material for spintronics applications.

Contribution

The study successfully synthesizes CrVTiAl with an exceptionally low magnetic moment and confirms its zero-moment ferrimagnetism, advancing spin-filter material development.

Findings

CrVTiAl has a low magnetic moment of 2.3×10⁻³ μ_B/f.u.

Magnetization is temperature-independent between 10 K and 400 K.

Transport measurements show metallic and semiconducting behavior.

Abstract

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 $a = 6.15 \AA$. Magnetization measurements reveal an exceptionally low moment of $\mu = 2.3 \times 10^{-3} \mu_B/f.u.$ at a field of $\mu_0 H = 2 T$, that is independent of temperature between T = 10 K and 400 K, consistent with the predicted zero-moment ferrimagnetism. Transport measurements reveal a combination of metallic and semiconducting components to the resistivity. Combining a zero-moment spin-filter material with nonmagnetic electrodes would lead to an essentially nonmagnetic spin injector. These results suggest that CrVTiAl is a promising candidate for further research in the field of spintronics.