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arXiv · 1609.03812

Identification of a Griffiths singularity in a geometrically frustrated antiferromagnet

Jitender Kumar·Soumendra Nath Panja·Shanu Dengre·Sunil Nair
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Abstract

We report the observation of a Griffiths Phase in the geometrically frustrated antiferromagnet DyBaCo${_4}$O${_{7+\delta}}$. Its onset is determined using measurements of the thermoremanent magnetization, which is shown to be superior to conventional in-field measurement protocols for the identification of the Griffiths Phase. Within this phase, the temporal relaxation of magnetization exhibits a functional form which is expected for Heisenberg systems, reflecting the nature of spin interactions in this class of materials. Interestingly, the effective Co${^{2+}}$/Co${^{3+}}$ ratio tailored by varying the oxygen non-stoichiometry $\delta$ is only seen to influence the antiferromagnetic ordering temperature ($T{_N}$), leaving the Griffiths Temperature ($T{_G}$) invariant.

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Jitender Kumar, Soumendra Nath Panja, Shanu Dengre, Sunil Nair. 2016-09-13. Identification of a Griffiths singularity in a geometrically frustrated antiferromagnet. https://doi.org/10.1103/physrevb.95.054401

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