The Modifications of Niobium Pentoxide

Abstract

Dedicated with sincere good wishes to Professor Wilhelni Klemm on his 70th birthdayNiobium pentoxide crystallizes in numerous modifications. The present paper describes their mode of formation, structures, and thermal properties.It should be particularly noted that the frequently coincident terms "modification" and "thermodynamic phase" a r e independent of one another. The definition does not exclude the possibility thatas discussedseveral modifications may occur in one phase, or sevsral phases may belong to the same modification. Obviously, however, this will not usually occur.The form Nb205-I1 observed by Slznfer and Royr31 and identified with Brnuer's M-Nb205 [21 is mentioned with the M-form. However, Nb205-I1 is, according to the interplanar [ 3 ] M .

Short crack initiation and growth at 600°C in notched specimens of Inconel718

“…Fatigue lifetimes to specimen fracture are listed in [33], estimates of the volume expansion factor will be calculated for the reaction:…”

Preparation and structure of alumina supported niobia model catalysts

“…(e.g., see [1][2][3][4][5][6][7][8]). In these catalysts, the niobia is basically used as a support for highly dispersed metal particles and typically forms Nb 2 O 5 crystallites, which may exist in different polymorphs depending on the heat treatment [9,10]. In addition, the niobia can also participate as an active component when added to other high surface area oxides such as alumina and silica, thus forming so called "monolayer" type catalysts based on the structural model where oxide spreads over support [11][12][13][14][15].…”

Micro‐Raman scattering in Nb2O5–TiO2 ceramics

“…1 The structure of the allotropic forms of niobium pentoxide is formed by blocks of corner-sharing NbO 6 octahedra in the a-c cross-section. 2 The blocks are interconnected by edge-sharing octahedra, yielding two sets of columns, one with its base at y D 0 and the other at y D b/2. Each octahedron contains one Nb ion in its center.…”