Electrical and magnetic properties of the complete solid solution series between SrRuO3 and LaRhO3: Filling t2g versus tilting

TL;DR

This study explores how the crystal structure, electrical conductivity, and magnetic properties evolve across the complete solid solution series between SrRuO3 and LaRhO3, revealing a metal-insulator transition and changes in magnetic behavior.

Contribution

It provides a comprehensive analysis of structural, electrical, and magnetic evolution in the SrRuO3-LaRhO3 series, highlighting the role of structural distortions and the localization of magnetism.

Findings

Metal-insulator transition occurs between x=0.1 and 0.2.

Magnetic order shifts from ferromagnetic to glassy with increasing x.

Structural distortions influence magnetic ground states.

Abstract

A complete solid solution series between the t2g^4 perovskite ferromagnet SrRuO3 and the diamagnetic t2g^6 perovskite LaRhO3 has been prepared. The evolution with composition x in (SrRuO3)(1-x)(LaRhO3)(x) of the crystal structure and electrical and magnetic properties has been studied and is reported here. As x increases, the octahedral tilt angle gradually increases, along with the pseudocubic lattice parameter and unit cell volume. Electrical resistivity measurements reveal a compositionally driven metal to insulator transition between x = 0.1 and 0.2. Ferromagnetic ordering gives over to glassy magnetism for x > 0.3 and no magnetic ordering is found above 2 K for x > 0.5. M_sat and Theta_CW decrease with increasing x and remain constant after x = 0.5. The magnetism appears poised between localized and itinerant behavior, and becomes more localized with increasing x as evidenced by the evolution of the Rhodes-Wohlfarth ratio. mu_eff per Ru is equal to the quenched spin-only S value across the entire solid solution. Comparisons with Sr(1-x)Ca(x)RuO3 reinforce the important role of structural distortions in determining magnetic ground state. It is suggested that electrical transport and magnetic properties are not strongly coupled in this system.