Correlating structural and magnetic ground states of 3d-5d based double perovskites: Evidence of two magnetic phase transitions

We present a detailed study on both the structural and magnetic properties of the Sr(2)RuMn(1-x)IrxO(6) double perovskite oxides with four different concentrations (x = 0, 0.25, 0.5 and 0.75). The main objective of the work is to study the effect of Ir substitution for Mn on the high-temperature crystallographic and low-temperature magnetic phases of the compounds. The phase purity was confirmed by the Rietveld analysis of the X-ray diffraction (XRD) pattern. The high temperature crystallographic information of the compounds was investigated by the help of high temperature X-ray diffraction and Raman spectroscopy. Signature of two structural phase transitions for x = 0.75 and one structural phase transition for x = 0 was seen. FESEM (Field emission scanning electron microscopy) with EDS (energy dispersive spectroscopy) of Ir-01 (x = 0.25) confirmed the presence of all the elements in the sample. The magnetic structure of all the samples have been studied at low temperature (5 K). The existence of two magnetic transitions for x = 0.5 and x = 0.75 are evident from the temperature dependent magnetization behavior.