2025/02/17 by Sajna Hameed, Hameed, S., I. Khayr +19
Materials Science · Physics and Astronomy · Biochemistry, Genetics and Molecular Biology · #Magnetic and transport properties of perovskites and related materials #Advanced Condensed Matter Physics #Geomagnetism and Paleomagnetism Studies
paper · pdf · doi:10.48550/arxiv.2502.12312
Neutron scattering, magnetometry, and muon spin rotation (μSR) measurements were performed to investigate the magnetic order and spin dynamics across the ferromagnet-to-paramagnet transition in the hole-doped Mott insulator Y1-xCaxTiO3. We find that the transition proceeds through a volume-wise phase separation into ferromagnetic and paramagnetic regions. Spin fluctuations with a characteristic timescale of ∼ 0.1 μs, as detected via μSR, are observed to appear at Ca concentrations x ≥ 0.10. The magnetic phase separation, accompanied by a modest dynamic response, represents a novel behavior in Mott systems near the loss of magnetic order. It is linked to a previously observed insulator-metal transition and the associated electronic phase separation into hole-poor Mott insulating and hole-rich metallic phases for 0 < x < 0.50. In particular, the x-dependence of the paramagnetic volume fraction strongly correlates with that of the volume fraction of the hole-rich metallic phase. The spin-wave spectra reveal a doping-induced crossover from isotropic to two-dimensional anisotropic exchange interactions, reflecting substantial changes in the orbital state with increasing Ca content.