Sr2FeMoO6 – A compound with many faces!

Compounds with a baffling number of elements appear dauntingly often in the literature, dominating a large part of condensed matter physics and chemistry and almost entirely the field of materials physics and chemistry. There is invariably a good reason for the choice of such complex combinations of elements, aimed at discovering startlingly new properties or at least improving on some existing ones. However, it is much less frequent to come across a single compound which presents multiple twists, challenging our understandings or expectations based on the prevalent wisdom. Sr2FeMoO6 is one such rare example. It also turns out that understanding the properties of this remarkable compound helps us to understand properties of several other, apparently unrelated, systems.

Sr2FeMoO6 is a magnetic metal with an unusually high Curie temperature (~ 420 K) and belongs to the double perovskite family of compounds. It shot in to fame a few years ago due to its remarkable magnetoresistive properties. [1] We discuss various aspects of this and related systems, emphasising novel aspects of its magnetism, magnetoresistance and disorder, based on our own work.[2-9]

This work has been contributed by S. Ray, D. Topwal, P. Mahadevan, T. Saha-Dasgupta, M. De Raychaudhury, A. Kumar, P. Sanyal, H.R. Krishnamurthy, C. Dasgupta, R. Cimino, S. Turchini, S. Zennaro and N. Zema, A. Zunger, K. Tanaka, M. Kobayashi, A. Fujimori, H. Kato, Y. Tokura and M. Avignon, C. Meneghini, F. Liscio, F. Bardelli, and S. Mobilio.
References:
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2.D.D. Sarma et al., Phys. Rev. Lett. 85, 2549 (2000).
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9. C. Meneghini, S. Ray, F. Liscio, F. Bardelli, S. Mobilio and D. D. Sarma, Phys. Rev. Lett. 103, 046403 (2009).