Reentrant Superspin Glass Phase in a La0.82Ca0.18MnO3 Ferromagnetic Insulator

Kumar, Anil P and Mathieu, R and Nordblad, P and Ray, Sugata and Karis, Olof and Andersson, Gabriella and Sarma, DD (2014) Reentrant Superspin Glass Phase in a La0.82Ca0.18MnO3 Ferromagnetic Insulator. In: PHYSICAL REVIEW X, 4 (1).

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Abstract

We report results of the magnetization and ac susceptibility measurements down to very low fields on a single crystal of the perovskite manganite, La-0.82 Ca-0.18 MnO3. This composition falls in the intriguing ferromagnetic insulator region of the manganite phase diagram. In contrast to earlier beliefs, our investigations reveal that magnetically (and in every other sense), this is a single- phase system with a ferromagnetic ordering temperature of around 170 K. However, this ferromagnetic state is magnetically frustrated, and the system exhibits pronounced glassy dynamics below 90 K. Based on measured dynamical properties, we propose that this quasi-long-ranged ferromagnetic phase, and the associated superspin glass behavior, is the true magnetic state of the system, rather than being a macroscopic mixture of ferromagnetic and antiferromagnetic phases, as often suggested. Our results provide an understanding of the quantum phase transition from an antiferromagnetic insulator to a ferromagnetic metal via this ferromagnetic state as a function of x in La1-xCaxMnO3, in terms of the possible formation of magnetic polarons.

Item Type:	Journal Article
Publication:	PHYSICAL REVIEW X
Publisher:	AMER PHYSICAL SOC
Additional Information:	Copyright for this article belongs to the AMER PHYSICAL SOC, USA
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	21 May 2014 09:39
Last Modified:	21 May 2014 09:55
URI:	http://eprints.iisc.ac.in/id/eprint/48951

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