Synthesis and physical properties of infinite-layer nickelate crystals

Infinite-layer (IL) nickelates are an emerging family of superconductors whose synthesis in thin film form is an established process by now, whereas the growth of their bulk counterparts remains a formidable challenge. In a previous study, we achieved the reduction of perovskite La_1-xCa_xNiO₃ single-crystals grown by a flux method under high external pressure to the IL phase La_1-xCa_xNiO₂ [1]. The typical lateral dimension of these crystals was 150 μm. As an advanced approach, we recently accomplished the reduction of millimeter-sized LaNiO₃ crystals obtained by optical floating zone growth under high oxygen gas pressure to the IL phase LaNiO₂ [2]. We will present our characterization of the crystalline, magnetic, and electronic properties of the LaNiO₂ crystals. Furthermore, we will provide an outlook on the realization of millimeter-sized PrNiO₂ crystals, as well as crystals with hole- and electron doping.