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arXiv · 1501.02334

Finite-size effects in the quasi-one-dimensional quantum magnets Sr$_{2}$CuO$_{3}$, Sr$_{2}$Cu$_{0.99}$M$_{0.01}$O$_{3}$ (M = Ni, Zn), and SrCuO$_{2}$

Koushik Karmakar·Surjeet Singh
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Abstract

We studied the finite-size effects on the magnetic behavior of the quasi-one-dimensional spin S = $\frac{1}{2}$ Heisenberg antiferromagnets Sr$_{2}$CuO$_{3}$, Sr$_{2}$Cu$_{0.99}$M$_{0.01}$O$_{3}$ (M = Zn and Ni), and SrCuO$_{2}$. Magnetic susceptibility data were analyzed to estimate the concentration of chain-breaks due to extrinsically doped defects and/or due to slight oxygen off-stoichiometry. We show that the susceptibility of Sr$_{2}$Cu$_{0.99}$Ni$_{0.01}$O$_{3}$ can be described by considering Ni$^{2+}$ as a scalar defect ($S_{eff}=0$) indicating that the Ni spin is screened. In Sr$_{2}$Cu$_{0.99}$Zn$_{0.01}$O$_{3}$ susceptibility analysis yields a defect concentration smaller than the nominal value which is in good qualitative agreement with crystal growth experiments. Influence of doping on the low-temperature long-range spin ordered state is studied. In the compound SrCuO$_{2}$, consisting of zigzag S = $\frac{1}{2}$ chains, the influence of spin frustration on the magnetic ordering and the defect concentration determined from the susceptibility data is discussed.

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Koushik Karmakar, Surjeet Singh. 2015-06-17. Finite-size effects in the quasi-one-dimensional quantum magnets Sr$_{2}$CuO$_{3}$, Sr$_{2}$Cu$_{0.99}$M$_{0.01}$O$_{3}$ (M = Ni, Zn), and SrCuO$_{2}$. https://doi.org/10.1103/physrevb.91.224401

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