2009/01/14 by Wanjun Jiang, X. Z. Zhou, Jiang, Wanjun +9
Biochemistry, Genetics and Molecular Biology · Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Condensed matter physics #FOS: Physical sciences #Ferromagnetism #Geomagnetism and Paleomagnetism Studies #Magnetic and transport properties of perovskites and related materials #Magnetic field #Magnetization #Materials Science (cond-mat.mtrl-sci) #Materials science #Metal #Metal–insulator transition #Paramagnetism #Phase (matter) #Phase boundary #Physics #Quantum mechanics #Strongly Correlated Electrons (cond-mat.str-el) #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · open access · doi:10.48550/arxiv.0901.1926
published in arXiv (Cornell University) (Cornell University) · 4 papges, 3 figures, all comments are welcome
arxiv created 2009/01/14 · openalex publication_date 2009/01/14 · arxiv updated 2009/12/01 · openalex created_date 2024/04/11 · openalex updated_date 2026/07/28
Detailed measurements of the magnetic and transport properties of the two La1-xCaxMnO3 (x = 0.18, x = 0.20) single crystals straddling the compositional metal-insulator transition boundary (0.18 < xc < 0.22) are summarized. The analysis of magnetization/susceptibility data reveals the occurrence of a second order/continuous ferromagnetic-paramagnetic phase transition described not only by nearest neighbour, 3-D Heisenberg model exponents (gamma = 1.387, beta = 0.365, delta = 4.783), but also with comparable values of the critical amplitudes in both the insulating and the metallic samples. These results support the assertion that double exchange cannot be the underlying mechanism supporting ferromagnetism in this composition range, and arguments are presented that the relevant interaction is ferromagnetic super exchange modulated by proximity to the orbitally ordered to disordered transition.