Structural properties and anisotropic electronic transport in SrIr O3 films
Abstract
Perovskite SrIr O3 (SIO) films epitaxially deposited with a thickness of about 60 nm on various substrate materials display a nearly strain-relieved state. Films grown on orthorhombic (110) DySc O3 (DSO) are found to display an untwinned bulklike orthorhombic structure. However, film deposition on cubic (001) SrTi O3 (STO) induces a twinned growth of SIO. Resistance measurements on the SIO films reveal only weak temperature dependence, where the resistance R increases with decreasing temperature T. Hall measurements show dominant electronlike transport throughout the temperature range from 2 to 300 K. At 2 K, the electron concentration and resistivity for SIO on STO amounts to ne=1.4 ×1020c m-3 and 1 mΩ cm. Interestingly, the film resistance of untwinned SIO on DSO along the [1-10] and the [001] direction differs by up to 25%, indicating pronounced anisotropic electronic transport. The anisotropy of the resistance increases with decreasing T and displays a distinct maximum at around 86 K. The specific T dependence is similar to that of the structural anisotropy √ (a2+b2 )/c of bulk SIO. Therefore, anisotropic electronic transport in SIO is very likely induced by the orthorhombic distortion. Consequently, for twinned SIO films on STO anisotropy vanishes nearly completely. The experimental results show that structural changes are very likely responsible for the observed anisotropic electronic transport. The strong sensitivity of the electronic transport in SIO films may be explained in terms of the narrow electronlike bands in SIO caused by spin-orbit coupling and orthorhombic distortion.
- Publication:
-
Physical Review B
- Pub Date:
- September 2018
- DOI:
- 10.1103/PhysRevB.98.115113
- arXiv:
- arXiv:1805.08473
- Bibcode:
- 2018PhRvB..98k5113K
- Keywords:
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- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- Phys. Rev. B 98, 115113 (2018)