Triscone Group

Perovskite rare earth nickelates (RNiO₃) have a rich phase diagram generated by changing the rare earth cation, R. The primary effect of this is to distort the structure, bending the nickel-oxygen-nickel bond angle. The exchange of one rare earth for another tunes the magnetic and electronic phases through a lattice distortion ^[1,2].

Much of the interest in nickelates is focused on predictions of high temperature superconductivity ^[3], their unusual antiferromagnetic order ^[4] and their sharp and highly controllable metal-insulator transition.

In Geneva we synthesise nickelate-based heterostructure as a base to study their intrinsic physics as well as to engineer novel properties arising from heterostructure effect such as unique magnetic structures, exchange bias and strain-, field- and light-tuning of the electronic state ^[5].

Bulk phase diagram of the perovskite nickelates RNiO₃ showing how the metal-insulator transition and paramagnetic-antiferromagnetic transition can be tuned in temperature by rare earth cation size.

[1]. M. Medarde, Journal of Physics: Condensed Matter 9, (1997)

[2]. G. Catalan, Phase Transitions 81, (2008)

[3]. J. Chaloupka and G. Khaliullin, Phys. Rev. Lett. 100, (2008)

[4]. V. Scagnoli et al, Phys. Rev. B 73, (2006)

[5]. S. Catalano et al, Reports on Progress in Physics 81, (2018)