Canted magnetic ground state of quarter-doped manganitesR_0.75Ca_0.25MnO₃(R  =  Y, Tb, Dy, Ho, and Er)

Abstract

Polycrystalline samples of the quarter-doped manganites R0.75Ca0.25MnO3 (R = Y, Tb, Dy, Ho, and Er) were studied by X-ray diffraction and AC/DC susceptibility measurements. All five samples are orthorhombic and exhibit similar magnetic properties: enhanced ferromagnetism below T1 (∼ 80 K) and a spin glass (SG) state below TSG (∼ 30 K). With increasing R 3+ ionic size, both T1 and TSG generally increase. The single crystal neutron diffraction results on Tb0.75Ca0.25MnO3 revealed that the SG state is mainly composed of a short-range ordered version of a novel canted (i.e. noncollinear) antiferromagnetic spin state. Furthermore, calculations based on the double exchange model for quarter-doped manganites reveal that this new magnetic phase provides a transition state between the ferromagnetic state and the theoretically predicted spin-orthogonal stripe phase.

Nonequilibrium magnetic properties in oxygen-rich LaMnO3 nanoparticles

“…From the magnetic point of view, nonequilibrium phenomena and slow dynamics are widely observed in perovskite manganites. For example, different glassy behaviors like conventional spin glass (SG) [7][8][9][10], superspin glass (SSG) [11,12], cluster glass (CG) [13][14][15] and surface SG [16] are frequently reported in perovskite manganites. However, the origins of these behav iors are diverse and complex owing to the competing ground states and the polyamorphism in these materials.…”