Lower valence fluorides of vanadium. 5. Dependence of structure and magnetic properties of tetragonal KxVF3 on composition

High-temperature DTA studies of AxMF3 compounds (, Rb, Cs; , Cr; and )

“…Products were analyzed optically by stereoscopic and polarized microscopy and further characterized by X-ray powder diffraction (25 1C) and magnetic measurements from 4.2 to 300 K [8][9][10][11][12]. Chemical analyses of K, Rb, Cs, V, and F in the A x VF 3 compounds were in agreement with calculated values [7][8][9][10].…”

“…The compounds studied were previously characterized in this laboratory [7][8][9][10][11][12]. Every precaution was taken to ensure that the samples were oxygen free.…”

“…The lower-valence fluorides of vanadium, A x VF 3 , and chromium, A x CrF 3 (where A ¼ K, Rb, or Cs), were first reported elsewhere [1][2][3][4][5][6], but their X-ray structures at 25 1C, along with those of Tl x VF 3 , were studied intensively in this laboratory [7][8][9][10][11][12]. Most of these materials demonstrate small crystal distortions and/or modulated structures, which are the consequence of concomitant ordering or displacive transitions that set in above 25 1C when they are cooled from higher temperatures.…”

“…The hettotype structure for K x VF 3 (tetragonal tungsten bronze) was deduced from magnetic susceptibility measurements [8]. The most probable space groups of all the other hettotype structures were obtained from Guinier-Hagg X-ray powder diffraction measurements made in this laboratory [23,24].…”

“…The b phase of K x VF 3 ðC 8 4v -P4 2 bcÞ is a hettotype of the tetragonal tungsten bronze structure [8]. The b phase of K x CrF 3 consists of three distinct structures at 25 1C [12].…”