On the magnetic structure of DyNiO3

摘要: The crystallographic structure of DyNiO{sub 3} has been investigated at T=200, 100, and 2 K from high-resolution neutron powder diffraction (NPD) data. We show that the is monoclinic, space group P2{sub 1}/n, metal-insulator transition temperature T{sub MI}=564 down to K. Ni atoms occupy two different sites 2d (Ni1) 2c (Ni2), whose valences, estimated bond-valence consideration, are +2.43(1) +3.44(1) K, respectively. This interpreted as result a partial charge disproportionation type 2Ni{sup 3+}->Ni1{sup (3-{delta})+}+Ni2{sup (3+{delta})+}, with {delta}{approx}0.55 T=2 magnetic studied NPD pattern well below establishment antiferromagnetic (AFM) ordering N}=154 sequential data collected 16 order defined by propagation vector k=(1/2,0,1/2). Two possible structures compatible intensities. In second solution both sublattices participate in order, Dy since it corresponds total Ni{sup 3+} 2+} 4+}. asmore » Dy. moments for Ni1 Ni2 1.8 (2) 0.8 mu{sub B}, These values also disproportionation. Dy{sup ions exhibit long-range 8 An abrupt contraction unit-cell volume observed this temperature, due magnetoelastic coupling. moment 7.87 (6) {mu}{sub B}. - Abstract: undergoes Below MI} monoclinic atoms, which present valence. It orders an Display Omitted« less