Muskan Sande

Affiliation: Sungkyunkwan University

Research Interests: Condensed Matter Physics, Solid State physics, Carbonaceous Nanomaterials, Quantum Physics

Title: Tuning the Magnetic Properties of Two Leg S=1⁄2 Quantum Spin Ladder Ba2CuTeO6 by Chemical Substitution Method

Abstract: The chemical substitution method is widely used for tuning material’s physical and magnetic properties. Tungsten substitution in the Two Leg S=½ Quantum Spin Ladder compound Ba2CuTe1-xWxO6, A2BB′O6 double perovskites, controls the magnetic properties dramatically by suppressing the magnetic ground state. This transition is based on substituting diamagnetic d 10 and d 0 cations into extended superexchange pathways that link magnetic cations. The d10/d0 effect is caused by differences in orbital hybridization in the B–O–B′–O–B superexchange pathways. Our studies investigate the magnetic properties of the two-leg S=½ quantum spin ladder compound Ba2CuTe1-xWxO6 through chemical substitution. By replacing Te 6+ with diamagnetic W6+ cations over a substitution range from x=0.0 to x=0.30, this study aims to understand how these substitutions impact the compound’s magnetic behavior. The substitution of W6+ for Te 6+ introduces significant variations in magnetic exchange interactions, analyzed using magnetic susceptibility, specific heat, Raman scattering, and electron spin resonance (ESR). X-ray diffraction (XRD) pattern and Rietveld analysis show the gradual change in the lattice parameters. The magnetic susceptibility shows a peak at approximately Tmax ~ 70 K, indicating significant spin-singlet correlations. As W content increases, the Curie-Weiss temperature rises, the Néel ordering temperature decreases, enhanced magnetic susceptibility at lower temperatures, and a reduction in spin-ladder correlations. Specific heat measurements display Schottky-like behavior, reflecting localized magnetic excitations and changes in spin-ladder dynamics. Raman scattering studies reveal unconventional magnetic scattering patterns, which change with increasing W content, demonstrating the impact of chemical substitution. ESR data shows a quasi-linear decrease in linewidth with increasing W content, suggesting enhanced quantum critical fluctuations and significant changes in spin dynamics. Our thorough analysis reveals that W substitution drives Ba2CuTe1-xWxO6 closer to a quantum-critical regime, demonstrating the intriguing ability to manipulate magnetic properties in spin-ladder systems.