Strain effects in manganite thin films

Jan Aarts 1Z Q. Yang Y Qin M Y. Wu H W. Zandbergen 

1. Kamerlingh Onnes Laboratory, Leiden University, Niels Bohrweg 2, Leiden 2333 CA, Netherlands

Abstract

The properties of manganite thin films strongly depend on both strain and disorder. Pure strain effects are difficult to distill, and therefore also strain engineering is difficult to perform. Moreover, the perovskite structure allows a large number of modifications, and in ultrathin films, the structure may even depend on the deposition technique. We discuss two different examples of the effects of strain. The first is in ultrathin films of La0.7Ca0.3MnO3 sputter-deposited on SrTiO3 where, below 5 nm, we find a tetragonal rather than an orthorhombic structure, and the absence of a metal-insulator transition. The second is in thin films of Pr0.5Ca0.5MnO3, also sputter-deposited on SrTiO3. Here we find that the charge ordering temperature Tco has increased significantly with respect to the bulk value. Preliminary results also indicate that Tco in the films is different from the orbital ordering temperature Too, contrary to the findings in bulk materials where both types of ordering are linked and occur at the same temperature.

 

Presentation: invited oral at E-MRS Fall Meeting 2003, Symposium D, by Jan Aarts
See On-line Journal of E-MRS Fall Meeting 2003

Submitted: 2003-07-26 10:20
Revised:   2009-06-08 12:55