TY - JOUR
T1 - Emergence of magnetic long-range order in frustrated pyrochlore Nd 2Ir 2O 7 with metal-insulator transition
AU - Tomiyasu, Keisuke
AU - Matsuhira, Kazuyuki
AU - Iwasa, Kazuaki
AU - Watahiki, Masanori
AU - Takagi, Seishi
AU - Wakeshima, Makoto
AU - Hinatsu, Yukio
AU - Yokoyama, Makoto
AU - Ohoyama, Kenji
AU - Yamada, Kazuyoshi
PY - 2012/3
Y1 - 2012/3
N2 - In this study, we performed powder neutron diffraction and inelastic scattering measurements of frustrated pyrochlore Nd 2Ir 2O 7, which exhibits a metal-insulator transition at a temperature T MI of 33 K. The diffraction measurements revealed that the pyrochlore has an antiferromagnetic long-range structure with propagation vector q 0 of (0, 0, 0) and that it grows with decreasing temperature below 15 K. This structure was analyzed to be of the all-in allout type, consisting of highly anisotropic Nd 3+ magnetic moments of magnitude 2.3 ± 0.4μ B, where μ B is the Bohr magneton. The inelastic scattering measurements revealed that the Kramers ground doublet of Nd 3+ splits below T MI. This suggests the appearance of a static internal magnetic field at the Nd sites, which probably originates from a magnetic order consisting of Ir 4+ magnetic moments. Here, we discuss a magnetic structure model for the Ir order and the relation of the order to the metal-insulator transition in terms of frustration.
AB - In this study, we performed powder neutron diffraction and inelastic scattering measurements of frustrated pyrochlore Nd 2Ir 2O 7, which exhibits a metal-insulator transition at a temperature T MI of 33 K. The diffraction measurements revealed that the pyrochlore has an antiferromagnetic long-range structure with propagation vector q 0 of (0, 0, 0) and that it grows with decreasing temperature below 15 K. This structure was analyzed to be of the all-in allout type, consisting of highly anisotropic Nd 3+ magnetic moments of magnitude 2.3 ± 0.4μ B, where μ B is the Bohr magneton. The inelastic scattering measurements revealed that the Kramers ground doublet of Nd 3+ splits below T MI. This suggests the appearance of a static internal magnetic field at the Nd sites, which probably originates from a magnetic order consisting of Ir 4+ magnetic moments. Here, we discuss a magnetic structure model for the Ir order and the relation of the order to the metal-insulator transition in terms of frustration.
KW - All-in all-out structure
KW - Localization and itinerancy
KW - Spin ice
KW - Spin-orbit interaction
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U2 - 10.1143/JPSJ.81.034709
DO - 10.1143/JPSJ.81.034709
M3 - Article
AN - SCOPUS:84858019751
VL - 81
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
SN - 0031-9015
IS - 3
M1 - 034709
ER -