MuSR and neutron diffraction studies on the tuning of spin-glass phase in partially ordered double perovskite SrMn$_{1-x}$W$_x$O$_3$

TL;DR

This study investigates how the spin-glass phase in SrMn1-xWxO3 can be tuned through structural and magnetic measurements, revealing a continuous phase transformation and the suppression of long-range order with increasing W content.

Contribution

It provides new insights into the tunability of spin-glass behavior in partially ordered double perovskites via chemical substitution and detailed neutron and muon studies.

Findings

Spin-glass transition temperature Tg decreases with W content.

No long-range magnetic order observed below Tg.

Structural transformation from simple perovskite to PODP phase with increasing x.

Abstract

Tunability of the partially ordered double perovskite (PODP) and coexisting spin-glass phase in SrMn1-xWxO3 (x=0.20 to 0.40) have been studied using neutron powder diffraction (NPD), muon spin relaxation (MuSR), and magnetic susceptibility (X) measurements. Structural studies reveal that SrMn1-xWxO3 undergoes a quasi-continuous transformation from simple perovskite (Pm-3m) to PODP (P21/n) phase as x increases. Xdc(T) and Xac(T) measurements show a sharp cusp-like peak at a spin glass transition, Tg. The muon relaxation rate ({\lambda}) peaks at Tg following a critical growth, given by {\lambda}={\lambda}(0).t-w [t=(T-Tg)/Tg]. However, no long-range magnetic order is observed in NPD below Tg. These measurements confirm a tunable spin-glass freezing in SrMn1-xWxO3 with Tg monotonously decreasing with W content, which we attribute to tuning the relative concentration of the coexisting Mn-O-Mn and Mn-O-W-O-Mn anti-ferromagnetic super-exchange pathways altering the geometric frustration.