MuSR study of the magnetic states in the perovskite and infinite-layer nickelates

The aim of this study is to clarify the magnetic ground state of the perovskite nickelate La1-xCaxNiO3 and infinite-layer nickelate La1-xCaxNiO2. Recently, it has been reported that the perovskite LaNiO3, which has been believed to be a strongly correlated nonmagnetic metal, exhibits an antiferromagnetic (AF) order. Using hole-doped La1-xCaxNiO3 samples prepared by our new method, we clarify whether the AF order/fluctuations exist in these samples, leading to the possible AF-fluctuation-mediated superconductivity in the perovskite nickelates. For the infinite-layer nickelate, we clarify the magnetic states of La1-xCaxNiO2 prepared by the low-temperature reduction using CaH2. This study would make progress to understand the relationship between the recently observed superconductivity and magnetism in the infinite-layer nickelates.