Spin-phonon interaction and magnetoelastic coupling associated with unusual cluster-glass states in YFe0.9Cr0.1O3

The magnetic, optical phonon behavior of the polycrystalline YFe0.9Cr0.1O3 (YFC-10), prepared by solid-state reaction route, had been studied via static and ac magnetization measurements and Raman spectroscopic techniques respectively. The results indicated that YFe0.9Cr0.1O3 undergoes unusual cluster-glass transitions at low temperatures viz. T-f1 (SG1) = 108 K (Freez.1) and T-f2 (SG2) = 30 K (Freez.2) coexisting with the long-range weak ferromagnetic (WFM) state. Raman spectroscopic (RS) measurements revealed 12 distinct modes of vibrations at all temperatures with 83-433 K. Interestingly, the freezing transition at (Tf1) is found to be accompanied by significant phonon renormalization. From the detailed analysis of the line-shape function of the Raman modes, the anomalous T-variation of the peak position and the linewidths suggests the existence of spin-phonon interaction in the present solid solution. Moreover the temperature dependent synchrotron X-ray diffraction studies between 10 and 300 K revealed the anomalous thermal variation of the lattice parameters and microscopic structural parameters such as super-exchange angles and (Fe/Cr)O6 octahedral bond lengths and bond angles at both the freezing transitions. Overall, the system exhibits the strong magnetoelastic and spin phonon coupling over a broad thermal regime viz. from Liquid. N-2 to temperatures above room temperature (RT = 300 K) which makes YFe(0.9)Cr(0.)1O(3) reliable for application purpose.

Automated summary

The polycrystalline YFe0.9Cr0.1O3 exhibits unusual cluster-glass transitions and weak ferromagnetic state at low temperatures. Raman spectroscopic and X-ray diffraction analyses indicate significant phonon renormalization and spin-phonon interactions in this solid solution. The system displays strong magnetoelastic and spin phonon coupling over a broad thermal regime.