Magnetic, Thermal, and Transport Properties of the Mixed Valent Vanadium Oxides LuV4O8 and YV4O8

TL;DR

This study investigates the magnetic, thermal, and transport properties of YV4O8 and LuV4O8, revealing a first-order phase transition at 50 K associated with structural changes and complex magnetic ordering.

Contribution

It provides detailed structural and property analysis of YV4O8 and LuV4O8, confirming a phase transition and elucidating magnetic behavior related to V atom dimerization.

Findings

First-order phase transition at 50 K with lattice parameter discontinuity

Partial V atom dimerization causes magnetic susceptibility drop

Bulk magnetic transitions occur below 90 K

Abstract

LV4O8 (L = Yb, Y, Lu) compounds are reported to crystallize in a structure similar to that of the orthorhombic CaFe2O4 structure-type, and contain four inequivalent V sites arranged in zigzag chains. We confirm the structure and report the magnetic, thermal, and transport properties of polycrystalline YV4O8 and LuV4O8. A first-order like phase transition is observed at 50 K in both YV4O8 and LuV4O8. The symmetry remains the same with the lattice parameters changing discontinously. The structural transition in YV4O8 leads to partial dimerization of the V atoms resulting in a sudden sharp drop in the magnetic susceptibility. The V spins that do not form dimers order in a canted antiferromagnetic state. The magnetic susceptibility of LuV4O8 shows a sharp peak at ~ 50 K. The magnetic entropies calculated from heat capacity versus temperature measurements indicate bulk magnetic transitions below 90 K for both YV4O8 and LuV4O8.