Magnetic behavior of Ba_{3}Cu_{3}Sc_{4}O_{12}

TL;DR

This study investigates the magnetic properties of Ba_{3}Cu_{3}Sc_{4}O_{12}, revealing long-range antiferromagnetic order at 16 K, influenced by competing interactions and sensitive to external magnetic fields, supported by experimental and theoretical analyses.

Contribution

It provides a comprehensive experimental and theoretical analysis of the magnetic interactions and order in Ba_{3}Cu_{3}Sc_{4}O_{12}, highlighting the presence of competing ferromagnetic and antiferromagnetic couplings.

Findings

Long-range antiferromagnetic order at ~16 K.

Magnetic transition temperature decreases with applied magnetic field.

Presence of competing ferromagnetic and antiferromagnetic interactions.

Abstract

The chain-like system Ba_{3}Cu_{3}Sc_4O_{12} has potentially interesting magnetic properties due to the presence of Cu^{2+} and a structure-suggested low-dimensionality. We present magnetization M versus magnetic field H and temperature T, T- and H-dependent heat-capacity C_{p}, ^{45}Sc nuclear magnetic resonance (NMR), muon spin rotation ({\mu}SR), neutron diffraction measurements and electronic structure calculations for Ba_{3}Cu_{3}Sc_{4}O_{12}. The onset of magnetic long-range antiferromagnetic order at T_{N} ~16 K is consistently evidenced from the whole gamut of our data. A significant sensitivity of T_{N} to the applied magnetic field H (T_{N}~0 K for H=70 kOe) is also reported. Coupled with a ferromagnetic Curie-Weiss temperature ({\theta}_{CW}~65 K) in the susceptibility (from a 100 K-300 K fit), it is indicative of competing ferromagnetic and antiferromagnetic interactions. These indications are corroborated by our density functional theory based electronic structure calculations where we find the presence of significant ferromagnetic couplings between some copper ions whereas AF couplings were present between some others. Our experimental data, backed by our theoretical calculations, rule out one-dimensional magnetic behaviour suggested by the structure and the observed long-range order is due to the presence of non-negligible magnetic interactions between adjacent as well as next-nearest chains.