title: Long-Range Antiferromagnetic Ordering in B-Site Ordered Double Perovskite Ca2ScOsO6.
abstract: A new Os-based B-site ordered double perovskite with the chemical composition of Ca2ScOsO6 was successfully synthesized. The crystal structure of the title compound was determined by employing the powder X-ray diffraction method and was found to crystallize in the monoclinic P21/n space group with the cell constants of a = 5.4716(1) Å, b = 5.6165(1) Å, c = 7.8168 (1) Å, and β = 89.889 (2)°. The temperature-dependent magnetic susceptibility data suggest that this novel S = (3)/2 compound undergoes an antiferromagnetic transition at ∼ 69 K. Fitting the high-temperature susceptibility data (100-300 K) to Currie-Weisse behavior showed C = 1.734 emu·K/mol (μeff = 3.72 bohr magnetons) and θ = -341 K, which is indicative of dominant antiferromagnetic interactions. Temperature-dependent specific heat measurements exhibit a λ shape anomaly at 69 K, which is consistent with a long-range ordering of the spins. Because of a triangular arrangement of antiferromagnetically ordered magnetic ions, the system exhibits some degree of geometric magnetic frustration (GMF), but not strongly. Spin-dimer analysis, employing extended Hückel theory, reveals that a dominant exchange interaction exists (along the a crystallographic axis in perovskite layer), which violates the perfect condition for GMF.
authors.affiliation: Department of Chemistry and Biochemistry, California State University , Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840, United States.
authors.forename: David D
authors.initials: DD
authors.lastname: Russell
authors.affiliation: Department of Chemistry, University of Southern California , 3620 McClintock Avenue, Los Angeles, California 90089-1062, United States.
authors.forename: Abbey J
authors.initials: AJ
authors.lastname: Neer
authors.affiliation: Department of Chemistry, University of Southern California , 3620 McClintock Avenue, Los Angeles, California 90089-1062, United States.
authors.forename: Brent C
authors.initials: BC
authors.lastname: Melot
authors.affiliation: Department of Chemistry and Biochemistry, California State University , Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840, United States.
authors.forename: Shahab
authors.initials: S
authors.lastname: Derakhshan