2020/06/23 by Ryoya Iwahara, Ryoma Sugawara, Rahmanto +6
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Coherence (philosophical gambling strategy) #Ferromagnetism #Isostructural #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #Quantum #Quantum critical point #Quantum fluctuation #Quantum phase transition #Spin (aerodynamics) #cond-mat.str-el
paper · pdf · doi:10.1103/physrevmaterials.4.074404
published as Phys. Rev. Materials 4, 074404 (2020) · 9 pages, 7 figures, to appear in Phys. Rev. Materials
arxiv created 2020/06/23 · openalex created_date 2020/06/25 · openalex publication_date 2020/07/08 · arxiv updated 2020/07/10 · openalex updated_date 2026/08/05
We demonstrate that the cluster-glass state emerges as ferromagnetic quantum criticality is avoided in the itinerant ferromagnet Sr_1\ensuremath-x(La0.5K0.5)xRuO3. In this compound, the ferromagnetic order is suppressed by increasing x and then disappears at the critical concentration: x=0.5. In this x range, the present study reveals that no prominent feature is ascribed to the quantum critical fluctuations in specific heat. Instead, ac magnetic susceptibility exhibits a broad peak due to spontaneous spin freezing, and the peak temperature depends significantly on the frequency of the applied ac magnetic field. Furthermore, specific heat is enhanced within a wide temperature range, whereas specific heat shows no salient anomaly associated with spin freezing. These features are characteristics of the formation of cluster glass; in particular, the observed frequency variations in ac magnetic susceptibility are well described by the Vogel-Fulcher law. We compare the features concerning the suppression of the ferromagnetic order in this doped compound with those in isostructural Ca- and La-doped SrRuO3 and suggest that a local correlated disorder effect and the very small coherence of itinerant Ru 4d electrons are responsible for the cluster-glass formation instead of the quantum phase transition in Sr_1\ensuremath-x(La0.5K0.5)xRuO3.