# Spin-glass behaviour in $$K_xRu_{4-y}Ni_yO_8$$ hollandite materials

Stimpson, Laura J. Vera, Jessica M., Powell, Stenning, Gavin B. G., Jura, Marek, Arnold, Donna C. (2018) Spin-glass behaviour in $$K_xRu_{4-y}Ni_yO_8$$ hollandite materials. Physical Review B: Condensed Matter and Materials Physics, 98 (17). Article Number 174429. ISSN 0163-1829. (doi:10.1103/PhysRevB.98.174429) (KAR id:70113)

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## Abstract

We report the synthesis and comprehensive ac and dc susceptibility measurements of $$K_xRu_{4-y}Ni_yO_8$$ hollandite. The value of the relative frequency shift, $$δT_f$$, has been determined as 0.025 which is within the range expected for spin-glass systems (0.005–0.06). Additionally, the characteristic flipping time of a single spin flip, $$τ_0$$, and the dynamical critical exponent, −zv, were determined to have values of 5.82 × 10$$^{−8}$$s and 6.1(3), respectively from the power law. While the value of $$τ_0$$ is comparatively very large, −zv is consistent with what is expected for spin-glass systems. Field-cooled hysteresis behavior demonstrates a small increase in the remnant magnetization (at 2 K) on increasing the strength of the cooling field, suggesting that the degree of short-range correlations increases consistent with the formation of larger spin clusters. Thermoremnant magnetization data indicate an exponential-like decay of the magnetization as a function of time with the remnant magnetization remaining nonzero. However, it is clear from these data that multiple components contribute to the decay behavior. Collectively, these data confirm spin-glass character for $$K_{0.73(3)}Ni_{1.9(5)}Ru_{2.1(5)}O_8$$ and clearly demonstrate that the magnetic behavior of this material is far from simplistic.

Item Type: Article 10.1103/PhysRevB.98.174429 frustrated magnetism; magnetic susceptibility; magnetism; alkaline earth metals; alloys; oxides; spin glasses; susceptibility measurements Q Science > QC Physics Divisions > Division of Natural Sciences > School of Physical Sciences Donna Arnold 15 Nov 2018 16:54 UTC 16 Feb 2021 13:59 UTC https://kar.kent.ac.uk/id/eprint/70113 (The current URI for this page, for reference purposes) https://orcid.org/0000-0003-0239-5790