Subsolidus Phase Relations in the System Fe–Ni–S at 450°C and 6 GPa

Refining sub-solidus phase relations in the systems CaO–RuO2–SiO2 and CaO–RuO2–V2O5

Subsolidus Phase Relations in BiO3/2–PrO11/6–CuO

The subsolidus phase relationships in the system Si,Al,Y/N,O were determined. Thirty‐nine compatibility tetrahedra were established in the region Si 3 N 4 ─AIN─Al 2 O 3 ─Y 2 O 3 . The subsolidus phase relationships in the region Si 3 N 4 ─AIN─YN─Y 2 O 3 have also been studied. Only one compound, 2YN:Si 3 N 4 , was confirmed in the binary system Si 3 N 4 ─YN. The solubility limits of the α′─SiAION on the Si 3 N 4 ─YN:3AIN join were determined to range from m = 1.3 to m = 2.4 in the formula Y m /3 Si 12‐ m Al m N 16 . No quinary compound was found. Seven compatibility tetrahedra were established in the region Si 3 N 4 ─AIN─YN─Y 2 O 3 .

Subsolidus phase relations and structures of solid solutions in the systems K2MoO4–Na2MoO4–MMoO4 (M = Mn, Zn)

Subsolidus phase relations have been determined in the systems SiO2–Cr–O and MgO–SiO2–Cr–O in equilibrium with metallic Cr, at 1100 to 1500°C and 0 to 2.88 GPa. The results show that there are no ternary phases in the SiO2–Cr–O system at these conditions, i.e., only the assemblage eskolaite–Cr–metal–quartz (or tridymite) is found. In the MgO–containing system, however, extensive substitution of Cr2+ for Mg is observed in (Mg, Cr2+)2SiO4 olivine, (Mg, Cr2+)2Si2O6 pyroxene, and (Mg, Cr2+)Cr2O4 spinel. Cr3+ levels in olivine and pyroxene are below detection limits. The pyroxene is orthohombic at XPxCr2+ <0.2, monoclinic at higher XPxCr2+. The structure of the spinels becomes tetragonally distorted at XPxCr2+ >0.2. The experimental data have been fitted to a thermodynamic model, and the authors obtained the mixing parameter (W) of Mg‐Cr2+ in olivine, pyroxene and spinel, and the relation between temperatures and free energies of formation for the end–members: Cr2+–olivine (Cr2SiO4), Cr2+–pyroxene (Cr2Si2O6) and Cr2+–spinel (Cr3O4).

Sub-solidus phase relations and a structure determination of new phases in the CaO–La2O3–TiO2 system

Subsolidus phase relations in the ternary system SnO 2–TiO 2–Y 2O 3

Subsolidus phase relations and the crystallization region of LiNbO 3 in the system Li 2O–B 2O 3–Nb 2O 5

摘要 采用固态反应法及改良固态反应法合成了一系列Y2O3-Eu2O3-SnO2体系中的试样，利用X射线粉末衍射法测定了Y2O3-Eu2O3-SnO2三元系固相线下的相关系.结果表明，Y2O3-Eu2O3二元系 关键词: Y2O3-Eu2O3-SnO2三元系 / 烧绿石型结构 / 激发光谱 / 发射光谱 Abstract Subsolidus phase relations in the ternary system Y2O3-Eu2O3-SnO2 have been investigated by means of X-ray powder diffraction. The samples are prepared by solid-state chemical reaction. The (Y1-xEux)2Sn2O7 and (Y1-xEux)2O3 binary systems form complete solid solutions with pyrochlore-type and cubic structures, respectively. The characteristic photoluminescence peaks observed from (Y1-xEux)2Sn2O７ and (Y1-xEux)2O3 compounds correspond to Eu3+ intra-4fn shell transitions. The difference between the emission and excitation spectra of (Y1-xEux)2Sn2O7 and (Y1-xEux)2O3 can be explained by considering the surroundings of crystallographic site occupied by Eu3+. Y2O3-Eu2O3-SnO2 ternary s Keywords: ystem / pyrochlore / excitation spectrum / emission spectrum 作者及机构信息 孙宝娟, 刘泉林, 梁敬魁, 纪丽娜, 张继业, 刘延辉, 李静波, 饶光辉 基金项目: 国家自然科学基金(批准号：50672007)资助的课题. Authors and contacts 参考文献 施引文献

Subsolidus phase relations have been determined in the systems SiO2-Cr-0 and MgO-SiO2-Cr-O in equilibrium with metallic Cr, at 1100–1500°C and 0–28·8 kbar. There are no ternary phases in the SiO2-Cr-O system at these conditions, ie. only the assemblage eskolaite + Cr-metal + SiO2 is found. However, in the MgO-containing system, extensive substitution of Cr2+ for Mg is observed in (Mg,Cr2+)2SiO4 olivine, (Mg,Cr2+)2Si2O6 pyroxene, and (Mg,Cr2+)Cr3+204 spinel. Cr 3+ levels in olivine and pyroxene are below detection limits. The pyroxene is orthorhombic at XpxCr2+ monoclinic at higher XpxCr2+. The structure of the spinels becomes tetragonally distorted at XpxCr2+ is limited by the breakdown of olivine to pyroxene + spinel + metal. This maximum amount increases strongly with increasing temperature, reaching XolCr2+ >0.2 at 1500°C and 4·8 kbar. Increasing pressure reduces the maximum XolCr2+. Increasing temperature also increases the maximum amounts of Cr2+ which substitute into pyroxene and spinel, indicating that end-member Cr2Si206 and Cr3O4 may become stable above ∽1650°C if melting does not intervene. Powder X-ray diffraction analysis of selected runs has been used to extract molar volumes of the Mg-Cr2+ solid solutions as a function of composition, which may be extrapolated to predict molar volumes for Cr2SiO4 (olivine), Cr2Si2O6 (ortho- and clino-pyroxene) and Cr2O4 (cubic spinel) of 47·7, 68·0 and 44·9 cm3, respectively. The experimental data have been fitted to a thermodynamic model, including free energies of formation for end member Cr2SiO4, Cr2Si2O6 and Cr3O4. This model is then used to predict the amounts of Cr2+ which can be expected in olivine in equilibrium with Cr-bearing spinel as a function of T, P and fo2. This amount increases strongly with temperature along standard T-fo2 buffer curves, and is sufficient to explain the observed high Cr contents of olivine from komatiites and diamond inclusions at reasonable terrestrial fo, values. The lower fo2 of the lunar environment results in significant Cr2+ in olivine being stable to much lower temperatures. The tendency for the oxidation state of Cr, and hence its geochemical properties, to change with temperature relative to other redox reactions makes it a potentially useful monitor of the temperatures of uppermantle processes, and is a significant factor in the differing styles of igneous differentiation in the Earth and Moon.

Subsolidus phase relations in the Co-rich region of the La–Co–Ti system

Melting and subsolidus phase relations in the MgSiO 3[sbnd]MgCO 3 system at high pressures: implications to evolution of the Earth's atmosphere

Subsolidus phase relations in the system BaOB 2O 3P 2O 5

Subsolidus phase relations have been determined in the CdO–InO1.5–SnO2 system at 1175°C. A cubic-bixbyite solution In2−2x(Cd,Sn)2xO3 (0 < x < 0.34), a cubic spinel solution (1−x)CdIn2O4–xCd2SnO4 (0 < x < 0.75), and an orthorhombic-perovskite solution Cd1−xSn1−xIn2xO3 (0 < x < 0.045) having the GdFeO3 structure have been discovered. The CdO phase field exists over a small range of InO1.5 (<3%) and SnO2 (<1%). Orthorhombic Cd2SnO4 (Sr2PbO4 structure) and rutile SnO2 appear to be point compounds with negligible solubility. The vertical section between spinel CdIn2O4 and orthorhombic Cd2SnO4 was determined between 900° and 1175°C. The spinel phase field (1−x)CdIn2O4–xCd2SnO4 was found to extend between x= 0 and x= 0.75 at 1175°C or x= 0.78 at 900°C. All of the phases in this system appear to allow small excess quantities of the donors In and/or Sn (vs cation stoichiometry) which may be the source of the electrons that give these oxides their n-type character. The electrical and optical properties of bulk and thin-film specimens in this system are compared and contrasted with each other and the relative merits of each are assessed.

Crystal chemistry and subsolidus phase relations in the system EuWO