Manifestation of the structural and the magnetic properties of transition metal oxide near quantum criticality

SrRuO₃ is an infinite-layer Ruddles den Popper series compound. This compound stabilizes in the orthorhombic Pbnm space group and has a Tc value around 160K . Ca-doped SrRuO3 shows the smeared quantum phase transition from ferromagnetic to paramagnetic behavior. The smeared quantum phase transition could be due to the disorder induced in the system as the Ca is doped on the Sr site. We synthesized the compound with chromium doping by using the solid-state method and XRD measurements were performed using 9 kW Rigaku Smart lab X ray diffractometer with Cu Kα radiation and Bragg Brentano-focused geometry. Rietveld refinement was carried out for all the three compounds, which suggests the compounds stabilize in a single orthorhombic Pbnm space group and is in a single phase. In the magnetic measurements M vs T, it clearly shows that the transition temperature for all samples increases significantly. In χ^-1 vs T, a downturn is observed in all the above compounds, which could be due to the Griffith regime around the critical point, and the Griffith's region becomes less strong as the applied field increases for all samples. Curie-Weiss fitting suggests an increase in ferromagnetic interaction with Cr doping. To relate the observed magnetic behavior with theory, we carried out DFT for spin polarization (FM phase and A-type, C-type and G-type) and thus we calculated the magnetic exchange constant (J).