Structural and Magnetic Study by Nonmagnetic (Ti4+ and Ga3+) Doping at Ru site in SrRuO3

Abstract

In this, we report the study of structural and magnetic behavior in Ru-based doped perovskite structure of SrRuO 3 and SrRu 0.9 M 0.1 O 3 (M = Ti and Ga). SrRuO 3 has an orthorhombic structure which has not change by Ga as well as Ti doping and also shows decreasing lattice parameters. The SrRuO 3 known to as an itinerant ferromagnet (FM) with Tc ~160K and having bifurcation between Zero-field-cooled (ZFC) and field-cooled (FC) magnetization below T c which decrease by nonmagnetic (Ti and Ga) doping. Further analysis of dc magnetization shows that the inverse susceptibility χ−1) in paramagnetic (PM) and high-temperature region fitted by modified Curie-Weiss law (CWL) in the form of χ(T) = χ 0 + [C/T-θ p ], where θ p is the Curie temperature. The effective PM moment $( \mu _{\mathrm {{eff}}} =[3 \mathrm {k}_{{\mathrm {B}}}\mathrm {C}/ \mathrm {N}] ^{1/2})$ and θ p decreases by nonmagnetic (Ti and Ga) doping. The χ−1(T) revealed some upward deviation by nonmagnetic (Ti and Ga) doping from perfect CWL behavior above T c because of the formation of FM clusters in the PM background which has characterized as Griffiths phase (GP). The critical exponent (β) fitting of FC magnetization of SrRuO 3 near T c shows as meanfield type behavior and fitted in the form of $\mathrm {M}( \mathrm {T}) = \mathrm {M}_{0}( \mathrm {T}_{\mathrm {{c}}}- \mathrm {T}) ^{\beta }$. By nonmagnetic (Ti and Ga) doping, the value of β has increased. The isothermal magnetization at 5 K of SrRuO 3 is showing hysteresis which is not changed by nonmagnetic (Ga and Ti) doping and also saturation moment $( \mu _{\mathrm {H}})$ has decreased. The Arrott’s plots are confirming FM nature with the value of spontaneous magnetization $( \mathrm {M}_{\mathrm {S}})$ which decreases by nonmagnetic (Ti and Ga) doping. The observation of Rhodes-Wohlfarth ratio shows, the value of $\mathrm {q}_{\mathrm {c}}/ \mathrm {q}_{\mathrm {s}}$ increased by nonmagnetic (Ti and Ga) doping, showing the itinerant nature of SrRu 0.9 M 0.1 O 3 (M = Ti and Ga) compounds increase, where $\mathrm {S}= \mathrm {q}_{\mathrm {{c}}} /2$ in $\mu _{{\mathrm {eff}}} =\mathrm {g}[ \mathrm {S}( \mathrm {S}+1 ) ] ^{1/2}$ and $\mathrm {q}_{\mathrm {{s}}} = \mu _{{\mathrm {H}}}$.