A resistance minimum and the electronic structures of some one-dimensional Pt-complexes at high pressures

The effect of pressure has been measured up to 650 kbar on the electrical resistance in six one-dimensional Pt-complexes, including two mixed valence ones. SrPt(CN)₄·2H₂O, MgPt(CN)₄·7H₂O and BaPt(CN)₄·4H₂O do not show a resistance minimum, contrary to other d⁸-metal complexes, suggesting a considerable contribution of π¹ orbitals of CN^- ligands to the conduction.     

Conductive phthalocyanines under very high pressure

Vanadyl, thorium, lead, copper, zinc and metal-free phthalocyanines become appreciably conductive under the static pressure of up to several hundred kilobars. The least resistivity observed is 0.1 $\text{Ω}$-cm for vanadyl phthalocyanine. There appear minima in the curves showing resistance change with pressure for vanadyl, thorium, lead and metal-free phthalocyanines.     

Polymorphism of ZnTe at elevated pressure

Simultaneous measurements of the electrical resistance and X-ray diffraction under pressure have revealed that ZnTe exhibits two subsequent structural transitions at approximately 85 and 130 kbar, accompanied by a conspicuous rise and drop in the resistance, respectively.     

A new application of Lagrange-Bürmann expansions. I. General principle

A new scheme is developed for improving the convergence of slowly convergent series solutions. The method is based on a transformation of variables of similarity form whereby the resulting composite function is constructed by its Lagrange-Bürmann expansion. It is the improved convergence of the new expansion that we take most advantage of in this method. The convergence of the Lagrange-Bürmann expansion as well as its inversion scheme is proved for analytic (object) functions. The inversion is required to recover from the Lagrange-Bürmann expansion the object function which is imbedded in the mapping functions. Several numerical examples demonstrate the improved convergence of the new method. The improvement owes much to the invariance properties of the mapping function under a group and the “built-in” feature of analytic continuation of the method. These features are elucidated in detail.     

Ferrielectric dielectric behaviour and the nature of phase transition of ammonium sulphate

Phenomenological treatments of ferrielectrics are made in terms of two non-equivalent sublattice polarizations in the paraelectric phase. Unlike the Curie-Weiss behaviour of usual proper ferro- and antiferro-electrics, the dielectric susceptibility does not depend linearly on temperature. Particularly in the case of a first order phase transition, the Curie-Weiss constant seems to be unusually small. As an example, the dielectric properties of (NH₄)₂SO₄, which was known to be a peculiar ferroelectric, is discussed from the ferrielectric point of view. The true Curie-Weiss constant is of a comparable order of magnitude to that of the order-disorder ferroelectric.     

Remarks on Third-Order ODEs Relevant to the Kuramoto-Sivashinsky Equation

We are interested in the third-order ordinary differential equations (ODEs) which are related to the Kuramoto-Sivashinsky equation. So-called steady solutions of the Kuramoto-Sivashinsky equation are known to admit several types; for example, bounded global solutions or periodic solutions. We show that, in addition to these, there exist solutions which blow up on bounded intervals. Moreover, for certain classes of these ODEs, the nonexistence of nontrivial bounded entire solutions is exhibited.