| AVS 56th International Symposium & Exhibition | |
| Thin Film | Monday Sessions |
| Session TF1-MoM |
| Session: | Thin Films: Growth and Characterization I |
| Presenter: | A. Gupta, The University of Alabama |
| Correspondent: | Click to Email |
A double perovskite is a perovskite with the general formula of A2BB’O6, where A is a divalent alkaline earth cation and B and B’ are transition-metal ions. Depending on the relative size and oxidation state, the B and B’ ions can be crystallographically completely ordered, making up a rocksalt-type lattice. La2NiMnO6 is an ordered double perovskite that is a ferromagnetic semiconductor with a TCM of 280 K. Recent studies of La2NiMnO6 in the bulk have revealed large magnetic-field induced changes in the resistivity and dielectric properties at temperatures as high as 280 K [1,2]. This is a much higher temperature than previously observed for such a coupling between the magnetic, electric, and dielectric properties in a ferromagnetic semiconductor. Substitution at the A site can also lead to multiferroic behavior in the double perovskites. Azuma et al. have succeeded in synthesizing the ‘designed’ compound Bi2NiMnO6 in the bulk under high pressure and established its multiferroic properties, with ferroelectric and ferromagnetic transition temperatures of 485 K and 140 K, respectively [3]. We have synthesized epitaxial thin films of La2NiMnO6 [4], Bi2NiMnO6 [5], and their heterostructures using the pulsed laser deposition (PLD) technique. A related ferromagnetic semiconductor, La2CoMnO6, has also been epitaxially stabilized [6]. High quality epitaxial films of these double perovskites are grown on lattice-matched substrates such as SrTiO3, NdGaO3 and LaAlO3. We have structurally characterized the double perovskite films using a variety of techniques. Additionally, the magnetic, electrical and magnetodielectric properties of the thin films and heterostructures have been studied in detail.
[1] N. S. Rogardo, J. Li, A. W. Sleight, and M. A. Subramanian, Adv. Mater. 17, 2225 (2005).
[2] H. Das, U. V. Waghmare, T. Saha-Dasgupta, and D. D. Sarma, Phys. Rev. Lett. 100, 186402 (2008).
[3] M. Azuma, K. Tanaka, T. Saito, S. Ishiwata, Y. Shimakawa, and M. Takano, J. Am. Chem. Soc. 127, 8889 (2005).
[4] H. Guo, J. Burgess, S. Street, A. Gupta, T. G. Calvarese, and M. A. Subramanian, Appl. Phys. Lett. 89, 022509 (2006).
[5] P. Padhan, P. LeClair, A. Gupta, and G. Srinivasan, J. Phys.: Condens. Matter 20, 355003 (2008).
[6] H. Z. Guo, A. Gupta, T. G. Calvarese, and M. A. Subramanian, Appl. Phys. Lett. 89, 262503 (2006).