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Royal Society University Research Fellow

BSc University of Barcelona
PhD University of Barcelona

Phase transitions in functional materials

My research focuses on phase transitions in functional materials whose thermal, structural, magnetic and electrical properties display strong coupling. These materials include multiferroics, and offer plenty of scope for interesting science and useful applications.

Caloric effects

Magnetocaloric, electrocaloric and mechanocaloric effects are reversible thermal changes that occur in magnetically, electrically and mechanically responsive materials due to changes in magnetic field, electric field and stress field. These caloric effects are largest near magnetic, ferroelectric and structural phase transitions, and promise new solid-state cooling technologies. I aim to develop new caloric materials systems by exploiting different types of coupling within and between materials.

Magnetoelectric effects

Magnetoelectric coupling permits an electrical polarization to be modified by magnetic field (direct effect), or a magnetization to be modified by electric field (converse effect). I investigate geometry-dependent strain-mediated coupling between ferroelectric materials and ferromagnetic materials near phase transitions. These systems yield large magnetoelectric effects at room temperature, and are interesting for applications in sensors, actuators and data storage.

A. Giant extrinsic magnetocaloric effect in thin-film La0.7Ca0.3MnO3 on a BaTiO3 substrate [Nature Materials 12, 52 (2013)].
B. Giant-strength intrinsic electrocaloric effect in a BaTiO3 single crystal [Advanced Materials 25, 1360 (2013)].


  • X Moya, E Defay, V Heine and ND Mathur, “Too cool to work”, Nature Physics 11, 202 (2015).
  • X Moya, S Kar-Narayan and ND Mathur, "Caloric materials near ferroic phase transitions", Nature Materials 13, 439 (2014).
  • X Moya, E Stern-Taulats, S Crossley, D González-Alonso, S Kar-Narayan, A Planes, Ll Mañosa and ND Mathur, "Giant electrocaloric strength in single-crystal BaTiO3", Advanced Materials 25, 1360 (2013).
  • X Moya, LE Hueso, F Maccherozzi, AI Tovstolytkin, DI Podyalovskii, C Ducati, LC Phillips, M Ghidini, O Hovorka, A Berger, ME Vickers, E Defay, SS Dhesi and ND Mathur, "Giant and reversible extrinsic magnetocaloric effects in La0.7Ca0.3MnO3 films due to strain", Nature Materials 12, 52 (2013).