Site dilution and charge disorder effect on physical properties in SrRu1−xGaxO3

Abstract

Here, we report an evolution of structural, magnetic and transport behavior in doped SrRu1−xGaxO3 (x 0.2). The nonmagnetic dopant Ga3+ (3d10) not only acts for magnetic site dilution in SrRuO3 but also modifies the Ru charge state and electronic density. Our studies show that Ga3+ substitution does not affect the original orthorhombic- Pbnm structure of SrRuO3 which is due to its matching ionic radii with Ru4+ . However, Ga3+ has a substantial effect on the magnetic behavior of SrRuO3 where it decreases both magnetic moment as well as magnetic transition temperature . Further, this dilution induces Griffiths phase behavior across and cluster-glass behavior at low temperature with higher concentration of doping. The magnetic critical exponent increases with x due to this site dilution effect. The Ga3+ induces an insulating state in SrRuO3 with x > 0.05. The charge transport in paramagnetic as well as in insulating state of samples can be well described with Mott’s modified variable-range-hopping model. The metallic charge transport just below in SrRuO3 obeys Fermi liquid behavior which breaks down at low temperature. We further find a correlation between field dependent magnetoresistance and magnetization through power-law behavior over the series.