Reduction of thermal conductivity in ferroelectric SrTiO3 thin films

Sarantopoulos, A. ; Saha, D. ; Ong, W.L. ; Magen, C. (Universidad de Zaragoza) ; Malen, J.A. ; Rivadulla, F.

Resumen: Bulk SrTiO3 is a quantum paraelectric in which an antiferrodistortive distortion below approximate to 105 K and quantum fluctuations at low temperature preclude the stabilization of a long-range ferroelectric state. However, biaxial mechanical stress, impurity doping, and Sr nonstoichiometry, among other mechanisms, are able to stabilize a ferroelectric or relaxor ferroelectric state at room temperature, which develops into a longer-range ferroelectric state below 250 K. In this paper, we show that epitaxial SrTiO3 thin films grown under tensile strain on DyScO3 exhibit a large reduction of thermal conductivity, approximate to 60% of at room temperature, with respect to identical strain-free or compressed films. The thermal conductivity shows a further reduction below 250 K, a temperature concurrent with the peak in the dielectric constant [J. H. Haeni et al., Nature (London) 430, 758 (2004)]. These results suggest that strain gradients in the relaxor and ferroelectric phase of SrTiO3 are very effective phonon scatterers, limiting the thermal transport in this material.

Idioma: Inglés

DOI: 10.1103/PhysRevMaterials.4.054002

Año: 2020

Publicado en: PHYSICAL REVIEW MATERIALS 4, 5 (2020), 054002 [5 pp]
ISSN: 2475-9953

Factor impacto JCR: 3.989 (2020)

Categ. JCR: MATERIALS SCIENCE, MULTIDISCIPLINARY rank: 134 / 333 = 0.402 (2020) - Q2 - T2

Factor impacto SCIMAGO: 1.439 - Physics and Astronomy (miscellaneous) (Q1) - Materials Science (miscellaneous) (Q1)

Financiación: info:eu-repo/grantAgreement/EC/H2020/734187/EU/Spin conversion, logic storage in oxide-based electronics/SPICOLOST
Financiación: info:eu-repo/grantAgreement/ES/MINECO/MAT2016-80762-R

Tipo y forma: Artículo (PostPrint)

Área (Departamento): Área Física Materia Condensada (Dpto. Física Materia Condensa.)