Magnetic Characterization of Variations in the Composition and Structure of NdSbxTe2-x-δ Crystals

Abstract

Topological semimetals (TSMs) have been proven to demonstrate electronic properties that are of interest for high-speed electronic and optoelectronic devices. The electron behavior in these materials resembles that of exotic particles, allowing for the study of these particles without the use of high-energy physics. Square-net TSMs in the MXZ family are of particular interest due to their topological electronic states that result from the square net structural motif, which is stabilized by delocalized bonding. Magnetic TSMs in the MXZ family, particularly rare-earth antimony telluride (RESbTe, RE = Rare Earth Metal) materials, have recently been explored to study the interplay between magnetism and topological electronic states. Studies of promising magnetic TSM candidates in the solid solution, GdSbxTe2-x-δ, have reported rich magnetic phase diagrams in addition to idealized band structures which have topological band crossings at the Fermi level (EF), with non-topological bands gapped away from EF due to charge density wave (CDW) distortions. However, due to the highly neutron-absorbing nature of Gd, the magnetic structure of GdSbxTe2-x-δ cannot be studied using the typical method of neutron diffraction. To circumvent this issue, NdSbxTe2-x-δ, has been proposed has a promising analog to help understand the magnetic structure of GdSbxTe2-x-δ, due to their presumed isostructural and isoelectronic properties. The following research serves as a preliminary analysis of the magnetism present in the NdSbxTe2-x-δ series. PPMS measurements are analyzed via a custom MATLAB program used to construct χ vs. T, M vs. H, and variable field M vs. T diagrams. Through an examination of the data yielded from systematically varying the Sb/Te composition, this research aims to characterize the evolving magnetic structure and phase behavior of the NdSbxTe2-x-δ series.