Publication

Getting more out of an incommensurately modulated structure: the example of K_5Yb(MoO_4)_4

Gervais Chapuis, Alla Arakcheeva
2006
Journal Articles

Abstract

A method based on the superspace approach is presented with the aim of generating a family of modular structures from a single incommensurately modulated structure. This approach based on the variation of the modulation vector q is applied to the generation of the K5Yb(MoO4)4, potassium ytterbium tetramolybdate, family of modular structures. The $\beta$ coefficient of the modulation vector q = $\beta b*$ is a temperature-dependent variable which determines the modification. Our method gives a unified frame to describe and explain the three temperature-dependent phases of K5Yb(MoO4)4. Phase can be represented as a polytypic modification with 1/2b*\le q\le 2/3b*; phases $\gamma$ (q = 1/2b*) and \alpha (q = 1b*) are the lowest and the highest temperature members of the K5Yb(MoO4)4 family, respectively.

Official source

https://infoscience.epfl.ch/entities/publication/f3c7ab33-be91-4f7e-af05-00a93faa63bc

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Gervais Chapuis, Alla Arakcheeva
2006
Journal Articles

Abstract

Official source

https://infoscience.epfl.ch/entities/publication/f3c7ab33-be91-4f7e-af05-00a93faa63bc

About this result

Related concepts (19)

Temperature

Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied on various reference points and thermometric substances for definition. The most common scales are the Celsius scale with the unit symbol °C (formerly called centigrade), the Fahrenheit scale (°F), and the Kelvin scale (K), the latter being used predominantly for scientific purposes.

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In mathematics, the Dedekind eta function, named after Richard Dedekind, is a modular form of weight 1/2 and is a function defined on the upper half-plane of complex numbers, where the imaginary part is positive. It also occurs in bosonic string theory. For any complex number τ with Im(τ) > 0, let q = e2πiτ; then the eta function is defined by, Raising the eta equation to the 24th power and multiplying by (2π)12 gives where Δ is the modular discriminant.

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