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Álvarez, Gabriel; Aso, Naofumi; Belanger, D. P.; Durand, Alice; Martı́n-Mayor, V.; Motoya, Kiyoichiro; Muro, Yuji

doi:10.1103/physrevb.86.024416

Cited by 1 publication

(2 citation statements)

References 31 publications

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“…The robust nature of the dynamics to dilution, and in particular disorder is analogous to several observations in dilute random field magnets and in particular the Fe x Zn 1−x F 2 series 46,175,176 , where sharp excitations are still observable for large amount of doping 49 . Unlike members of the Fe x Zn 1−x F 2 series closer to the percolation threshold (x p ∼ 0.24) that exhibit spin glass behavior 6,45,49,170 , Fe 0.5 Zn 0.5 F 2 assumes long range antiferromagnetic order in zero field with a T N corresponding to half of that of FeF 2 177,178 . The appearance of long range antiferromagnetic order as measured by DC susceptibility with a µ o H ext = 0.5 T supports the claim that α-CoV 3 O 8 is not close to the percolation threshold, where even the smallest external field destroys long range order, as is the case for M x Zn 1−x F 2 , where M = Co 2+ and Fe 2+ 131 .…”

Section: Comparison Between α-Cov3o8 and Randommentioning

confidence: 99%

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Ordered magnetism in the intrinsically decorated jeff=12α−CoV3O8

et al. 2018

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The antiferromagnetic mixed valence ternary oxide α-CoV3O8 displays disorder on the Co 2+ site that is inherent to the Ibam space group resulting in a local selection rule requiring one Co 2+ and one V 4+ reside next to each other, thus giving rise to an intrinsically disordered magnet without the need for any external influences such as chemical dopants or porous media. The zero field structural and dynamic properties of α-CoV3O8 have been investigated using a combination of neutron and x-ray diffraction, DC susceptibility, and neutron spectroscopy. The low temperature magnetic and structural properties are consistent with a random macroscopic distribution of Co 2+ over the 16k metal sites. However, by applying the sum rules of neutron scattering we observe the collective magnetic excitations are parameterized with an ordered Co 2+ arrangement and critical scattering consistent with a three dimensional Ising universality class. The low energy spectrum is well-described by Co 2+ cations coupled via a three dimensional network composed of competing ferromagnetic and stronger antiferromagnetic superexchange within the ab plane and along c, respectively. While the extrapolated Weiss temperature is near zero, the 3D dimensionality results in long range antiferromagnetic order at T N ∼ 19 K. A crystal field analysis finds two bands of excitations separated in energy at ω ∼ 5 meV and 25 meV, consistent with a j eff = 1 2 ground state with little mixing between spin-orbit split Kramers doublets. A comparison of our results to the random 3D Ising magnets and other compounds where spin-orbit coupling is present indicate that the presence of an orbital degree of freedom, in combination with strong crystal field effects and well-separated j eff manifolds may play a key role in making the dynamics largely insensitive to disorder.

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Section: Comparison Between α-Cov3o8 and Randommentioning

confidence: 99%

“…In contrast to the disordered systems described above, where the disorder is a consequence of an addition external to the original system (e.g. doping 6,[44][45][46][47][48] , porous media 32,37,38 , etc. ), and thus can be finely tuned 54 , the disorder in α-CoV 3 O 8 is simply inherent to its Ibam crystal structure.…”

Section: Introductionmentioning

confidence: 99%