Active control of thermal conductivity in mesophases and complex oxides

Abstract

This PhD thesis explores the development of thermal switches: materials whose thermal conductivity can be precisely and reversibly controlled on demand by the application of an external stimulus. Four strategies have been investigated, based on a different physical mechanism and material platform: photoisomerization in azobenzene-based mesophases, topotactic redox transformations in (Ca,Sr)FeO3 thin films, electric-field driven oxygen vacancy engineering in charge-transfer oxides, and polar topology manipulation in PbTiO3/SrTiO3 superlattices. The results establish heat transport as a functional, tunable property, opening pathways for programmable thermal materials in advanced technologies.