Perovskite-type complex oxides are a family of compounds that have attracted growing interest because of the variety of tunable physical properties, which makes them attractive for technological applications in different areas [1]. Thermal transport can reveal important information about phonons, which can play an important role in electronic collective transport properties. At LQMEC, we have implemented advanced experimental platforms for the investigation of thermal transport in a range of quantum materials under multiple extreme conditions.
In this talk, I will present and discuss our recent investigations of thermal diffusivity in a representative of this class of oxides: the Barium Bismuthate BaBiO3 (BBO) [2]. BBO exhibits an insulating ground state with a still debated origin and a superconducting state upon hole-doping, besides being predicted to host a topological insulating (TI) state upon electron doping [3]. A complex relation between electronic and lattice degrees of freedom has  been called into question in an attempt to explain the electronic states of this compound [4]. Our thermal conductivity experiments found a remarkably low value at room temperature (~1W/mK), a plateau at intermediate temperatures, and an unexpected ~T2 power law at low temperatures (T < 5K), reminiscent of a glass-like behavior [2].
I will finally present our current experimental efforts in pushing our investigation of thermal conductivity towards thin films limit by employing the 3-Omega technique, aiming at investigating how structural distortion induced by strain can tune the heat transport.

REFERENCES
1.    AS. Bhalla et al. Mat. Res. Innov. 4.1, 3, (2000).
2.    Henriques et al. New Physics: Sae Mulli, 73 (12), 1183 (2023).
3.    RL. Bouwmeester, et al. Rev. in Phys., 6, 100056. (2021).
4.    B. G. Jang et al, Physical Review Letters 130, 136401 (2023)
 
We acknowledge the support of FAPESP (Grants n. 2018/19420-3, 2018/08845-3, 2022/01742-0, 2021/00625-7, 2022/03262-5), UGPN-2020 and CNPq (402919/2021-1).