Pressure induced transition from a spin glass to an itinerant ferromagnet in half doped manganite Ln0.5Ba0.5MnO3 (Ln=Sm and Nd) with quenched disorder

TL;DR

This study demonstrates that applying pressure to half doped manganites with quenched disorder induces a transition from a spin glass insulator to an itinerant ferromagnet, highlighting the role of pressure in tuning phase boundaries.

Contribution

It reveals how pressure influences phase transitions in disordered manganites, emphasizing the pressure-controlled suppression of multicritical phase boundaries.

Findings

Sm0.5Ba0.5MnO3 transitions from spin glass to ferromagnetic metal under pressure.

Tc increases rapidly with pressure for both Sm and Nd compounds.

Quenched disorder enhances the pressure effect near the multicritical region.

Abstract

The effect of quenched disorder on the multiphase competition has been investigated by examining the pressure phase diagram of half doped manganite Ln0.5B0.5MnO3 (Ln = Sm and Nd) with A-site disorders. Sm0.5Ba0.5MnO3, a spin glass insulator at ambient pressure, switches to a ferromagnetic metal with increasing pressure, followed by a rapid increase of the ferromagnetic transition temperature Tc. The rapid increase of Tc was confirmed also for Nd0.5Ba0.5MnO3. These observations indicate that the unusual suppression of the multicritical phase boundary in the A-site disordered system, previously observed as a function of the averaged A-site ionic radius, is essentially controlled by the pressure and hence the band width. The effect of quenched disorder is therefore much enhanced with approaching the multicritical region.