Phase relations in the CaMnO system

Examination of Perovskite Structure CaMnO3-δwith MgO Addition as Oxygen Carrier for Chemical Looping with Oxygen Uncoupling Using Methane and Syngas

“…The highly possible phases which contain Ca could be CaO or Ca 2 MnO 4-. Horowitz and Longo suggested that CaO and CaMnO 3 were the phases in Ca-Mn-O system at temperature below 1300 ∘ C when the Ca to Mn molar ratio was above 1, and the oxygen partial pressure 0.2 atm [48]. On the other hand, several research groups identified small amount of CaMn 2 O 4 which coexited with CaMnO 3− during synthesis of CaMnO 3-when using stoichiometric molar amount of Ca and Mn during production.…”

Phase Chemistry in the Ca‐Mn‐Sb‐O System at 1160–1250 °C

“…In the ternary system Ca-Mn-O, the phase relationships were studied in detail in air in the temperature range from 700 to 2600°C. [1] The introduction of antimony considerably complicates the composition of this quasi-ternary system because of inclusion of binary (Ca x Sb y O z , Mn x Sb y O z ) and ternary (Ca x Mn y Sb z O m ) oxides and some solid solutions into this system. As some binary compounds of Mn and Sb and Ca and Sb are formed and exist only at low temperatures, the analysis of the Ca-Mn-Sb-O system in this study is limited only to high temperatures.…”

“…In the ternary oxides forming this system, manganese exists in the form of Mn 4+ , Mn 3+ , and (or) Mn 2+ cations, and antimony exists mainly as Sb 5+ . [1][2][3][4][5][6] Such various oxidation states of manganese characteristic for a wide interval of temperatures, apparently, are defined by the chemical nature of oxides of manganese (II), (III) and (IV), calcium, and antimony as components of chemical reactions.…”

“…The former four compounds are stable at high temperatures, whereas Ca 2 Mn 3 O 8 decomposes in air at 810°C. [1] In the trivalent state, manganese exists in the compound CaMn 2 O 4 , on the basis of which a solid solution is formed at high temperatures. This oxide has a marokite structure and is generally referred to as a post-spinel phase crystallizing in an orthorhombic syngony.…”

Properties of FeCo Nanopowder Prepared by Chemical Synthesis

“…Several methods for preparation FeCo have been developed recently , eg chemical or physical vapor deposition, sol-gel technique, laser pyrolysis. Thermal decomposition of oxalate precursor was applied as well [4]. In our work the different procedure for preparation of binary Fe-Co oxalate was used, namely creation solid state mixture by segregation from solution allows mixing of the different metal species on an atomic scale.…”