TY - JOUR
T1 - Spin and orbital contributions to magnetically ordered moments in 5 d layered perovskite Sr2 IrO4
AU - Fujiyama, S.
AU - Ohsumi, H.
AU - Ohashi, K.
AU - Hirai, D.
AU - Kim, B. J.
AU - Arima, T.
AU - Takata, M.
AU - Takagi, H.
PY - 2014/1/10
Y1 - 2014/1/10
N2 - The ratio of orbital (L) and spin (S) contributions to the magnetically ordered moments of a 5d transition metal oxide, Sr2IrO4 was evaluated by nonresonant magnetic x-ray diffraction. We applied an improved experimental setting that minimized the experimental error, in which we varied only the linear polarization of incident x ray at a fixed scattering angle. Strong polarization dependence of the intensity of magnetic diffraction was observed, from which we conclude that the ordered moments contain substantial contribution from the orbital degree of freedom with the ratio of YLY/YSY∼5.0, evidencing the pronounced effect of spin-orbit coupling. The obtained ratio is close to, but slightly larger than the expected value for the ideal Jeff=1/2 moment of a spin-orbital Mott insulator, |YJ1/2|Lz|J1/2Y|/|YJ1/2|Sz|J1/2Y|=4, which cannot be accounted for by the redistribution of orbital components within the t2g bands associated with the elongation of the IrO6 octahedra.
AB - The ratio of orbital (L) and spin (S) contributions to the magnetically ordered moments of a 5d transition metal oxide, Sr2IrO4 was evaluated by nonresonant magnetic x-ray diffraction. We applied an improved experimental setting that minimized the experimental error, in which we varied only the linear polarization of incident x ray at a fixed scattering angle. Strong polarization dependence of the intensity of magnetic diffraction was observed, from which we conclude that the ordered moments contain substantial contribution from the orbital degree of freedom with the ratio of YLY/YSY∼5.0, evidencing the pronounced effect of spin-orbit coupling. The obtained ratio is close to, but slightly larger than the expected value for the ideal Jeff=1/2 moment of a spin-orbital Mott insulator, |YJ1/2|Lz|J1/2Y|/|YJ1/2|Sz|J1/2Y|=4, which cannot be accounted for by the redistribution of orbital components within the t2g bands associated with the elongation of the IrO6 octahedra.
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U2 - 10.1103/PhysRevLett.112.016405
DO - 10.1103/PhysRevLett.112.016405
M3 - Article
AN - SCOPUS:84892429257
SN - 0031-9007
VL - 112
JO - Physical Review Letters
JF - Physical Review Letters
IS - 1
M1 - 016405
ER -