Exchange bias and spin-phonon coupling in complex glassy layered perovskite SrLaMn0.5Ni0.5O4

In the present work, single-layered polycrystalline Ruddlesden-Popper oxide, SrLaMn0.5Ni0.5O4 (SLMNO) has been synthesized and characterized. X-ray diffraction and Raman spectroscopy revealed tetragonal crystal structure (I4/mmm) with lattice parameters of a = b = 3.8388 (4) Å and c =12.5593 (2) Å. XPS analysis confirms Mn4+/Ni2+ as the major valance state in SLMNO. Temperature evolution of dc magnetization suggests a ferromagnetic ordering below 130 K followed by a glassy like behaviour below 13 K. The ac susceptibility measurement corroborates the dc magnetization data and confirms cluster glass behavior at lower temperatures. Interestingly, SLMNO exhibits a negative exchange bias of ∼ 0.075 kOe at 5 K under field cooling of 50 kOe and also shows the existence of spin-phonon coupling.