Coupled electronic and magnetic phase transition in the infinite-layer phase LaSrNiRuO4
Topochemical reduction of the ordered double perovskite LaSrNiRuO6 with CaH2 yields LaSrNiRuO4, an extended oxide phase containing infinite sheets of apex-linked, square-planar Ni1+O4 and Ru2+O4 units ordered in a checkerboard arrangement. At room temperature the localized Ni1+ (d9, S = 1/2) and Ru2...
Main Authors: | , , , , |
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Format: | Journal article |
Published: |
American Chemical Society
2016
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Summary: | Topochemical reduction of the ordered double perovskite LaSrNiRuO6 with CaH2 yields LaSrNiRuO4, an extended oxide phase containing infinite sheets of apex-linked, square-planar Ni1+O4 and Ru2+O4 units ordered in a checkerboard arrangement. At room temperature the localized Ni1+ (d9, S = 1/2) and Ru2+ (d6, S = 1) centers behave paramagnetically. However, on cooling below 250 K the system undergoes a cooperative phase transition in which the nickel spins align ferromagnetically, while the ruthenium cations appear to undergo a change in spin configuration to a diamagnetic spin state. Features of the low-temperature crystal structure suggest a symmetry lowering Jahn–Teller distortion could be responsible for the observed diamagnetism of the ruthenium centers. |
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