Negas Taki, Roth Robert S
Institute for Materials Research, National Bureau of Standards, Washington, D.C. 20234.
J Res Natl Bur Stand A Phys Chem. 1969 Jul-Aug;73A(4):431-442. doi: 10.6028/jres.073A.034.
Phase relations in the system SrO-"chromium oxide" were determined in air and 1 atm O (1 atm = 1.013 × 10 N/m) and are shown as isobaric projections on the SrO-CrO pseudobinary. At both oxygen pressures, the system consists of three joins in the SrO-CrO-oxygen ternary, (1) SrO-SrCrO, (2) SrCrO-SrCrO, and (3) SrCrO-CrO. The former is binary from 1065 °C to liquidus temperatures in air and includes a eutectic near 79 mol percent SrO (in terms of SrO-CrO starting materials). SrCrO melts congruently at 1453 °C. Below 1065 °C in air, phase relations are complicated by reactions with atmospheric water vapor resulting in the formation of SrCrO (OH) which decomposes to SrO and SrCrO above 1065 °C. In air, below 775 °C, SrCrO reacts with water vapor and oxygen to form SrCrO (OH) and SrCrO. Water vapor reactions are restricted in 1 atm O. The SrCrO-SrCrO join contains a binary eutectic between 69-70 mol percent SrO but liquidus relations are ternary below 69 (air) and 68 (oxygen) mol percent SrO, as reduction of Cr occurs. Likewise, the SrCrO-CrO join is not binary at solidus and liquidus temperatures. In air, SrCrO melts at 1251 °C to CrO plus liquid with release of oxygen. In oxygen, the compound melts at 1283 °C with evolution of oxygen.
在空气和1个大气压氧气（1个大气压 = 1.013×10⁵ N/m²）中测定了SrO - “氧化铬”体系的相关系，并以等压投影的形式展示在SrO - CrO伪二元系上。在两种氧压下，该体系在SrO - CrO - 氧三元系中由三个连接组成：(1) SrO - SrCrO₄，(2) SrCrO₄ - Sr₂CrO₅，以及(3) Sr₂CrO₅ - Cr₂O₃。前者在空气中从1065℃到液相线温度为二元体系，并且在SrO含量接近79摩尔百分比（基于SrO - CrO起始原料）处包含一个共晶点。SrCrO₄在1453℃时发生一致熔融。在空气中低于1065℃时，与大气中的水蒸气发生反应使相关系变得复杂，导致形成SrCrO₄(OH)，其在高于1065℃时分解为SrO和SrCrO。在空气中，低于775℃时，SrCrO₄与水蒸气和氧气反应形成SrCrO₄(OH)和SrCrO。在1个大气压氧气中，水蒸气反应受到限制。SrCrO₄ - Sr₂CrO₅连接在SrO含量为69 - 70摩尔百分比之间包含一个二元共晶点，但在SrO含量低于69（空气）和68（氧气）摩尔百分比时，液相线关系为三元系，因为发生了Cr的还原。同样，Sr₂CrO₅ - Cr₂O₃连接在固相线和液相线温度下不是二元体系。在空气中，Sr₂CrO₅在1251℃时熔化为Cr₂O₃加液体并释放氧气。在氧气中，该化合物在1283℃时熔化并释放氧气。
