Intrinsic exchange bias effect in phase-separated La_0.82Sr_0.18CoO₃single crystal

Abstract

We report a study of the exchange bias of a high quality perovskite cobaltite La 0.82 Sr 0.18 CoO 3 single crystal with spin glass (SG) like nature. According to the dependence of exchange bias field on the cooling field, an antiferromagnetic (AFM) interfacial exchange coupling constant at the spin-glass region J i ≈ −0.68 meV was found. The size of the FM regions t FM ≈ 9 nm was estimated in the spin-glass system from the inverse proportion of exchange bias field H EB to the size of the FM regions.

Exchange bias effect in alloys and compounds

“…interior spontaneous phase separation, investigation was performed in a single crystal with composition, La 0.82 Sr 0.18 CoO 3 where EB effect was ascribed to pinning effect at the FM and SG interface [187]. The analysis of H cool dependence of H E using equation ( 7) provided coupling constant ≈ -0.68 meV at the interface between FM and SG phases and average size of FM clusters ≈ 0.9 nm.…”

Exchange bias effect and intragranular magnetoresistance in Nd0.84Sr0.16CoO3

“…The EB effect has also been evidenced through the systematic shifts in magnetoresistance-field (MR-H) curve which is limited to the bilayer or multilayer films only [11,12,13,14]. Recently, EB effect has been reported in few compounds attributed to the grain interior spontaneous phase separation where EB effect was reported through the shift in the magnetic hysteresis loop [9,10,15,16,17,18,19] In this article, we report a new paradigm of EB effect in a polycrystalline compound, Nd 0.84 Sr 0.16 CoO 3 through the shifts in the MR-H curve. We observe the strong EB effect involved with a fairly large intragranular MR where the value of EB field is found to be much larger than the observation measured through the shift in the magnetic hysteresis loop.…”

Crystal structures and magnetic properties of strontium and copper doped lanthanum ferrites

“…Very significant is the presence of open hysteresis loops for all compositions indicative of weak ferromagnetism. The weak ferromagnetism in LaFeO 3 based perovskites is a well documented effect [10,[12][13][14][15], while the appearance of hysteresis has been less investigated, and it has been observed at low temperatures in LaFeO 3 , [26][27][28], in La 1 À x Sr x FeO 3 [16] and in similar doped La-perovskites [29][30][31][32] (except for the Mn-based ones). Such weak ferromagnetism is associated with structural features and the multi-cationic nature of these oxide.…”