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arXiv · 1103.3563

Evidence for impurity-induced frustration in La2CuO4

P. Carretta·G. Prando·S. Sanna·R. De Renzi·C. Decorse·P. Berthet
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Abstract

Zero-field muon spin rotation and magnetization measurements were performed in La2Cu{1-x}MxO4, for 0<x< 0.12, where Cu2+ is replaced either by M=Zn2+ or by M=Mg2+ spinless impurity. It is shown that while the doping dependence of the sublattice magnetization (M(x)) is nearly the same for both compounds, the N\'eel temperature (T_N(x)) decreases unambiguously more rapidly in the Zn-doped compound. This difference, not taken into account within a simple dilution model, is associated with the frustration induced by the Zn2+ impurity onto the Cu2+ antiferromagnetic lattice. In fact, from T_N(x) and M(x) the spin stiffness is derived and found to be reduced by Zn doping more significantly than expected within a dilution model. The effect of the structural modifications induced by doping on the exchange coupling is also discussed.

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P. Carretta, G. Prando, S. Sanna, R. De Renzi, C. Decorse, P. Berthet. 2011-03-18. Evidence for impurity-induced frustration in La2CuO4. https://doi.org/10.1103/physrevb.83.180411

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