title: Antisite disorder driven spontaneous exchange bias effect in La(2-x)Sr(x) CoMnO₆ (0  ⩽  x  ⩽  1).
abstract: Doping at the rare-earth site by divalent alkaline-earth ions in perovskite lattice has witnessed a variety of magnetic and electronic orders with spatially correlated charge, spin and orbital degrees of freedom. Here, we report an antisite disorder driven spontaneous exchange bias effect as a result of hole carrier (Sr(2+)) doping in La(2-x)Sr(x)CoMnO6 (0  <  x  <  1) double perovskites. X-ray diffraction and Raman spectroscopy have evidenced an increase in disorder with the increase of Sr content up to x  =  0.5 and thereby a decrease from x  =  0.5 to 1. X-ray absorption spectroscopy has revealed that only Co is present in the mixed valence of Co(2+) and Co(3+) states with Sr doping to compensate the charge neutrality. Magnetotransport is strongly correlated with the increase of antisite disorder. The antisite disorder at the B-site interrupts the long-range ferromagnetic order by introducing various magnetic interactions and instigates reentrant glassy dynamics, phase separation and canted type antiferromagnetic behavior with the decrease of temperature. This leads to a novel magnetic microstructure with unidirectional anisotropy that causes a spontaneous exchange bias effect that can be tuned with the amount of antisite disorder.
authors.affiliation: Cryogenic Engineering Centre, Indian Institute of Technology, Kharagpur-721302, India.
authors.forename: J
authors.initials: J
authors.lastname: Krishna Murthy
authors.forename: K D
authors.initials: KD
authors.lastname: Chandrasekhar
authors.forename: H C
authors.initials: HC
authors.lastname: Wu
authors.forename: H D
authors.initials: HD
authors.lastname: Yang
authors.forename: J Y
authors.initials: JY
authors.lastname: Lin
authors.forename: A
authors.initials: A
authors.lastname: Venimadhav