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Manganite/Cuprate Superlattice as Artificial Reentrant Spin Glass
Author(s) -
Ding Junfeng,
Cossu Fabrizio,
Lebedev Oleg I.,
Zhang Yuqin,
Zhang Zhidong,
Schwingenschlögl Udo,
Wu Tom
Publication year - 2016
Publication title -
advanced materials interfaces
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.671
H-Index - 65
ISSN - 2196-7350
DOI - 10.1002/admi.201500676
Subject(s) - manganite , condensed matter physics , materials science , superlattice , spin glass , curie temperature , ferromagnetism , magnetism , cuprate , heterojunction , superconductivity , physics
Emerging physical phenomena at the unit‐cell‐controlled interfaces of transition‐metal oxides have attracted lots of interest because of the rich physics and application opportunities. This work reports a reentrant spin glass behavior with strong magnetic memory effect discovered in oxide heterostructures composed of ultrathin manganite La 0.7 Sr 0.3 MnO 3 (LSMO) and cuprate La 2 CuO 4 (LCO) layers. These heterostructures are featured with enhanced ferromagnetism before entering the spin glass state: a Curie temperature of 246 K is observed in the superlattice with six‐unit‐cell LSMO layers, while the reference LSMO film with the same thickness shows much weaker magnetism. Furthermore, an insulator–metal transition emerges at the Curie temperature, and below the freezing temperature the superlattices can be considered as a glassy ferromagnetic insulator. These experimental results are closely related to the interfacial spin reconstruction revealed by the first‐principles calculations, and the dependence of the reentrant spin glass behavior on the LSMO layer thickness is in line with the general phase diagram of a spin system derived from the infinite‐range SK model. The results of this work underscore the manganite/cuprate superlattices as a versatile platform of creating artificial materials with tailored interfacial spin coupling and physical properties.