Phase diagram for the binary system K/sub 2/CrO/sub 4/-CaCrO/sub 4/

Journal Article · Sun Oct 31 23:00:00 EST 1976 · J. Solid State Chem.; (United States)

DOI:https://doi.org/10.1016/0022-4596(76)90178-X· OSTI ID:7315193

Karnowsky, M M; Clark, R P; Biefeld, R M

The phase diagram for the binary system K/sub 2/CrO/sub 4/--CaCrO/sub 4/ has been determined for CaCrO/sub 4/ concentrations up to 60 mole %, using the techniques of differential thermal analysis, X-ray diffraction, and drop calorimetry. Essential features of the phase diagram are: the solid--solid phase transition for pure K/sub 2/CrO/sub 4/ at 670/sup 0/C, ..beta..-K/sub 2/CrO/sub 4/ in equilibrium ..cap alpha..-K/sub 2/CrO/sub 4/; a eutectoid reaction at 14 mole % CaCrO/sub 4/ and 548/sup 0/C, ..beta..-K/sub 2/CrO/sub 4/ in equilibrium ..cap alpha..-K/sub 2/CrO/sub 4/ + K/sub 2/CrO/sub 4/ . CaCrO/sub 4/; a peritectoid event at 50 mole % CaCrO/sub 4/ and 640/sup 0/C, ..beta..-K/sub 2/CrO/sub 4/ + CaCrO/sub 4/ in equilibrium K/sub 2/CrO/sub 4/ . CaCrO/sub 4/; and a eutectic reaction at 51 mole % CaCrO/sub 4/ and 678/sup 0/C, L in equilibrium ..beta..-K/sub 2/CrO/sub 4/ + CaCrO/sub 4/. X-ray diffraction studies lead to the determination of the unit cell dimensions for the K/sub 2/CrO/sub 4/ . CaCrO/sub 4/ double salt, a C-centered monoclinic form with a/sub 0/ = 7.615(6) A, b/sub 0/ = 22.797(15) A, C/sub 0/ = 9.777(9) A, ..beta.. = 115.45(5)/sup 0/.

• Research Organization: Sandia Labs., Albuquerque, NM
• OSTI ID: 7315193
• Journal Information: J. Solid State Chem.; (United States), Journal Name: J. Solid State Chem.; (United States) Vol. 19:3; ISSN JSSCB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
BINARY MIXTURES
CALCIUM COMPOUNDS
CHROMATES
CHROMIUM COMPOUNDS
COHERENT SCATTERING
DIAGRAMS
DIFFERENTIAL THERMAL ANALYSIS
DIFFRACTION
DISPERSIONS
EUTECTICS
MIXTURES
OXYGEN COMPOUNDS
PHASE DIAGRAMS
POTASSIUM COMPOUNDS
SCATTERING
THERMAL ANALYSIS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION