Physico-chemical properties of chromium trioxide and its suboxides

Gas sensing response analysis of p-type porous chromium oxide thin films

“…around 200 C, which on further heating gets converted to Cr 0.85 +3 Cr 0.15 +6 O 1.75 at 450 C. 29,30 At a higher temperature, under normal oxygen partial pressures Cr 3+ is the most stable oxidation state, hence CrO 3 when heated in air, gets converted into CrO 1.516 at 450 C. On further heating, it nally converts into Cr 2 O 3 at 850 C by losing excess oxygen. 35 Thus, the XPS studies conrm the existence of a higher Cr +6 contribution in the lms and underlines the key role of the gas atmosphere and temperature, which predominantly determine the surface chemical composition of the lms. Furthermore the non-stoichiometry is also reected in the O1s XPS spectra of the lms (Fig.…”

New mixed-valence chromium structure type: NH4Cr(CrO4)2

“…The title compound constitutes a new structure type among the Cr(III)/Cr(VI) ternary oxides, the NH 4 -type. (33) 0.87 (7) 2.01 (7) 2.870 (16) 169 (13) Symmetry transformations used to generate equivalent atoms: (i) Àx, Ày, Àz+1 (ii) x; Ày þ 1 2 ; z (iii) Àx; y þ 1 2 ; Àz þ 1. …”

“…One of the intermediate decomposition products is CrO 2 , a well-known ferromagnetic compound. Further, many oxides with compositions between the trioxide and the monoxide were suggested as a result of these studies; both Cr 2 O 5 and Cr 3 O 8 have frequently been reported [6,[16][17][18]. Many questions remain concerning the identities of the various stable intermediate oxides, their characterisation and whether non-stoichiometric regions exist.…”

“…Intermediate binary oxides prepared by thermal decomposition of CrO 3 under different conditions have been subject to numerous studies [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] during the past 50 years. The starting material, CrO 3 , contains tetrahedrally coordinated Cr(VI), while the final thermal decomposition product is Cr 2 O 3 with octahedrally coordinated Cr(III).…”

Study of Thermal Behavior Of Cr(NO3)39H2O in N2 Atmosphere Using TGA

“…Due to their chemical and physical characteristics, chromium compounds are used in a wide variety of industries all over the world [1,2,3,4,5,6] . One of the most important characteristics of the chromium concerns its reactions to acids and bases as well as to air, a process known as oxidation.…”