Observation of a Metallic Antiferromagnetic Phase and Metal to Nonmetal Transition inCa3Ru2O7<

Abstract

Single crystal Ca 3 Ru 2 O 7 shows a metallic antiferromagnetic phase intermediate between a first-order metal to nonmetal transition at T M 48 K and the antiferromagnetic ordering (Néel) temperature, T N 56 K. The metallic antiferromagnetic phase is predicted within various Mott-Hubbard models. Magnetization and electrical resistivity reveal strongly anisotropic metamagnetism in the nonmetallic antiferromagnetic phase. The charge and spin excitations are strongly coupled: The H-T phase diagrams determined by magnetization and magnetoresistivity are indistinguishable and reveal a multicritical point. The heat capacity of Ca 3 Ru 2 O 7 suggests it is a highly correlated electron system. [S0031-9007(97)02552-0]

Charge density wave formation accompanying ferromagnetic ordering in quasi-one-dimensional BaIrO3

“…The discontinuity in r c (T) at T c1 is a metal-nonmetal transition connecting metallic-like behavior for T c1 Ͻ T Ͻ T c2 Ϸ 80 K with non-metallic for T Ͻ T c1 (r c 2 K =r c 27 K Ϸ 55). This transition is nearly identical to that seen in the bilayered 4d TMO Ca 3 Ru 2 O 7 [5,6], though the comparable discontinuity in r(T) for Ca 3 Ru 2 O 7 at T M 48 K is not restricted to one principal axis as in BaIrO 3 . It is noted that r C (T) in the metallic state (30 Ͻ T Ͻ 80 K) is larger than the Mott limit.…”

“…However, the ferromagnetism at T c3 175 K in BaIrO 3 [4] appears to be accompanied by and possibly driven by a collective electronic excitation or at least partial gapping of the Fermi surface. This demonstrates once again the strong coupling between spin and charge in the heavy (4d-and 5d-based) TMOs [5][6][7]. BaIrO 3 has a highly anisotropic quasi-one-dimensional structure [8][9][10] and this gives rise, in our single crystal samples, to large anisotropy of r(T), the electrical resistivity, with the quasi-one-dimensional axis, the c-axis, having much lower resistivity.…”

Evolution of magnetism in single-crystalCa2Ru1−xIrxYuan1, Terzic2, Wang3 et al. 2015Phys. Rev. BSelf Cite493751View full textAdd to dashboardCite

“…[23] The structures of Ca 2 Ru 1−x Ir x O 4 were determined using a Nonius Kappa CCD x-ray diffractometer at 90 K. Structures were refined by full-matrix least squares using the SHELX-97 programs [24]. All structures affected by absorption and extinction were corrected by comparison of symmetry-equivalent reflections using the program SADABS [24].…”

Anisotropic Magnetoresistance in AntiferromagneticSr2IrO4

“…Our sample is a single crystal of Sr 2 IrO 4 (1.5 × 1 × 0.5 mm 3 ) synthesized via a self-flux technique [17]. The insert of Fig.…”