Electronic properties in itinerant ferromagnet SrRu_1−x Ti _x O₃

Abstract

SrRuO 3 presents a rare example of ferromagnetism among the 4d based oxides. While the nature of magnetic state in SrRuO 3 is mostly believed to be of itinerant type, recent studies suggest a coexistence of both itinerant and localized model of magnetism in this material. Here, we have investigated the evolution of magnetic state in doped SrRu 1−x Ti x O 3 through studying the critical behavior using standard techniques such as, modified Arrott plot, Kouvel-Fisher plot and critical isotherm analysis across the magnetic transition temperature T c . The substitution of nonmagnetic Ti 4+ (3d 0 ) for Ru 4+ (4d 4 ) would simply dilute the magnetic system apart from modifying the electron correlation effect and the density of states at Fermi level. Surprisingly, T c does not change with x. Moreover, our analysis show the exponent β related to spontaneous magnetization increases while the exponents γ and δ related to initial inverse susceptibility and critical magnetization, respectively decrease with Ti substitution. The estimated exponents do not match with any established theoretical models for universality classes, however, the exponent obey the Widom relation and the scaling behavior. Interestingly, this particular evolution of exponents in present series has similarity with that in isoelectronic doped Sr 1−x Ca x RuO 3 . We believe that site dilution by Ti leads to formation magnetic clusters which causes this specific changes in critical exponents.

Evolution of ferrimagnetism against Griffiths singularity in calcium ruthenate

“…Whereas the Crdoped samples exhibit R-H hysteresis and the hysteretic nature increases with Cr doping. The overall nature of the negative MR resembles fairly well with other established ferromagnetic Ruthenates [25,71,72]. Interestingly, a sharp jump in MR is noticed (for CRCO10 and CRCO15) much above the coercive field (switching field H s ∼ 44 kOe).…”

Ferromagnetic insulating behavior at low temperature induced by Sn doping in the ceramic SrRuO3

“…22 As for Ru site, magnetic (Fe 3+ , Co 3+ , Ir 4+ , Tc 4+ , and Mn 3+ ) and nonmagnetic (Ti 4+ , Pb 4+ , and Ga 3+ ) element substitution has been investigated. 18,[23][24][25][26][27][28][29] Magnetic elements participate in existing interactions, whereas nonmagnetic elements directly disrupt the coupling of 4d orbitals of Ru 4+ to the 2p orbitals of O 2− . It was reported that 10% Cr-doped SRO can increase T C to 188 K. 30 And the enhanced T C is attributable to broaden bandwidth due to the hybridization between Cr 3d and Ru 4d.…”