Scalar order: possible candidate for order parameters in skutterudites

Abstract

Phenomenological Landau analysis shows that the properties of ordered phases in some skutterudites are consistently accounted for by a scalar order parameter which preserves the cubic symmetry, even in the ordered phase. A universal value is found for the anisotropy ratio of the transition temperature in a magnetic field, homogeneous magnetization, and induced staggered magnetization. The difference in magnetic behavior between PrFe${}_4$P${}_{12}$ and PrRu${}_4$P${}_{12}$ near their phase transitions is explained within a single framework. For the low-field phase of PrFe${}_4$P${}_{12}$, the scalar order with the ${\Gamma }_{1g}$ symmetry can explain (i) the absence of field induced dipoles perpendicular to the magnetic field, (ii) isotropic magnetic susceptibility in the ordered phase, (iii) the field angle dependence of the transition temperature, and (iv) the splitting pattern of the ${}^{31}$P nuclear magnetic resonance (NMR) spectra. It is proposed how the order parameter in SmRu${}_4$P${}_{12}$ is identified by NMR analysis of a single crystal.

4 pages, 4 figures

Cited by in corpus (3)

• On the Symmetry of Low-Field Ordered Phase of PrFe4P12 : 31P NMR
• Phenomenological theory of a scalar electronic order: application to skutterudite PrFe4P12
• Gap opening with ordering in PrFe4P12 studied by local tunneling spectroscopy