[en] This article reviews primarily the quasi-low dimensional behavior of molybdenum bronzes, but also some new results on other transition metal bronzes, particularly of the vanadium and tungsten phosphate bronzes are discussed. (author). 168 refs.; 29 figs.; 5 tabs

[en] In this article the behavior of Charge Density Waves (CDW's) in quasi one-dimensional compounds, e.g. the blue bronzes, is treated in a classical picture. Starting from the phase description of the elastic deformations of CDW's in the continuum model, a basis for a theory of elasticity and plasticity of CDW's is sketched. A description of topological defects of CDW's is given, including walls, dislocations and disclinations. finally the response of a of a CDW to an applied electric field of increasing intensity is described. (H.W.). 53 refs.; 28 figs

[en] Although the molybdenum bronzes and oxides were first synthesized many years ago, it is only recently that they have been rediscovered as quasi one- or two-dimensional metallic oxides. This book provides a review of their properties centered around charge density wave instabilities. Different aspects, including chemical, structural and physical properties are covered. A special emphasis is placed on nonlinear transport due to the sliding of charge density waves. The volume also includes theoretical views of the charge density wave transition in relation to structural defects and to the notion of breaking of analyticity, both of which are of interest for all charge density wave solids. (author). refs.; figs.; tabs

[en] The physical properties, mostly transport, of the low dimensional molybdenum bronzes and oxides are reviewed. After a brief theoretical background the quasi 1D properties, including charge-density wave transport of the blue bronzes A_0.30MoO₃, and the quasi 2D systems, purple bronzes A_0.9Mo₆O₁₇ and Mo_nO_3n-1 oxides, are discussed. (H.W.). 172 refs.; 69 figs.; 4 tabs

[en] This review covers the structural instabilities of the molybdenum bronzes A_xMo_yO_z, where A is a monovalent metal, and of the Molybdenum oxides Mo_nO_3n-1. Two families of Mo bronzes are considered: A_0.3MoO₃ with A= K, Rb, or Tl ( the blue bronzes), and A_0.9Mo₆O₁₇ with A= K, Na, Tl or Li (the purple bronzes). First some basic features of the charge-density wave instability and periodic lattice distortion of low dimensional conductors are recalled. Then their manifestation in the 1D case (blue bronzes) and 2D case (purple bronzes and Mo oxides are detailed. (H.W.). 123 refs.; 31 figs.; 2 tabs

[en] The oxide bronzes have the general formula A_xMO_n, where A is an electropositive, readily ionizable element, such as an alkali metal, and MO_n the transition metal oxide corresponding to the highest oxidation state of the M cation. The structural arrangements of these compounds allow one to vary the amount of inserted cations over a large range without any structural change. The sublattices forming the structure may have a dimensionality lower than three, and consequently the chemical and physical properties are also direction dependent. This article discusses the low-dimensionality properties of oxide molybdenum bronzes. (H.W.). 72 refs.; 39 figs.; 2 tabs

[en] This chapter is an experimental review of ac conductivity of the 'blue bronze' K_0.3MoO₃, which is taken to be a prototype material for a discussion of charge-density wave (CDW) motion. The bulk of the review concentrates on low-frequency measurements. Three frequency regimes are discussed. The first regime is termed the dielectric relaxation regime (dc-10 MHz) where the dynamics can be described as the decay of an induced polarization of the CDW resulting from local deformations of the CDW. In this frequency regime on can neglect the effects of inertia and take the CDW mass to be zero. The dominant energy loss mechanism results because of screening of the CDW deformations by the normal electrons. The second frequency regime (10 - 100 GHz) is dominated by the pinned phase mode of the CDW. In this regime one must include inertia in describing the CDW dynamics. The effective mass of the CDW causes an inertial roll-off in the ac response with a frequency dependence which is approximately described by a response of a rigid CDW. At frequencies near the pinning energy, electrostatic screening is less important as a damping mechanism and deformations of the CDW do not occur. Damping mechanisms in this frequency realm are temperature dependent and are less well-understood. The third frequency regime is the far-infrared frequency region between the pinned phase mode and the single electron energy gap. This regime has been studied less intensely than the two low frequency regimes, however large resonances in infrared measurements of (TaSe₄)₂I and K_0.30MoO₃ suggesting further modes may be present in CDW materials. (author). 87 refs.; 16 figs.; 2 tabs