Effect of chemical pressure on the electronic phase transition in Ca1−xSrxMn7O12 films
Abstract
We demonstrate how chemical pressure affects the structural and electronic phase transitions of the quadruple perovskite CaMn7O12 by Sr doping, a compound that exhibits a charge-ordering transition above room temperature making it a candidate for oxide electronics. We have synthesized Ca1−xSrxMn7O12 (0 ≤ x ≤ 0.6) thin films by oxide molecular beam epitaxy on (LaAlO3)0.3(SrAl0.5Ta0.5O3)0.7 (LSAT) substrates. The substitution of Sr for Ca results in a linear expansion of the lattice, as revealed by X-ray diffraction. Temperature-dependent resistivity and X-ray diffraction measurements are used to demonstrate that the coupled charge-ordering and structural phase transitions can be tuned with Sr doping. An increase in Sr concentration acts to decrease the phase transition temperature (T*) from 426 K at x = 0 to 385 K at x = 0.6. The presence of a tunable electronic phase transition, above room temperature, points to the potential applicability of Ca1−xSrxMn7O12 in sensors or oxide electronics, for example, via charge doping.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 01, 2017
- Source ID
- 10.1063/1.4994089
Entities
People
- A. Herklotz
- A. Huon
- Dongkyu Lee
- Ho Nyung Lee
- M. R. Fitzsimmons
- S. J. May
Organizations
- Army Research Office
- Drexel University
- Oak Ridge National Laboratory
- United States Department of Energy
- University of Tennessee