Synthesis of Mixed Valenced Oxide Minerals

混合价氧化物矿物的合成

• 批准号: 01470055
• 负责人: KIKUCHI Takeshi
• 金额: $ 3.2万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-01470055/
• 关键词: Solid solution; Mineral synthesis; Hausmannite; Spinel; Mixed valency; Jacobsite; Cryptomelane; Fluorite structure; 酸化マンガン; 酸素分圧; ブラウン鉱; ハウスマンナイト

(1) Making of Phase Equilibrium Diagram of the System Jacobsite (MnFe_2O_4) -Hausmannite (Mn_3O_4)Phase diagram of the system jacobsite-hausmannite was made by solid state reactions under hematite-magnetite oxygen buffers. Compositions of the two phase region where a cubic phase and a tetragonal phase coexisted were determined by electron microprobe analysis. A thermodynamical approach revealed that the equilibrium concentration relations among chemical constituents such as Mn^<2+>, Fe^<2+>, Mn^<3+>, Fe^<3+> and vacancy of metal in the cubic phase.(2) Observation of Thermal Decompostion Behavior of Pyrolusite by Means of Hihg Temperature Powder X-ray DiffractometerTwo kinds of thermally different pyrolusite (S) and (D) are known ; (S) shows one endothermic peak about 650^ﾟC and (D) has two endothermic peaks about the same temperature. High temperature X-ray measurements for these showed that (S) decomposed at about 650^ﾟC and transformed to bixbyite (alpha-Mn_2O^3) exclusively, whereas (D) converted to gamma-Mn_2O_3 and Mn_5O_8 in addition to bixybite. Thermal behavior of (D) was explicable from the oxygen deficiency in (D).(3) Thermal Transformation of Cryptomelane (A_xMn_8O_<16>. nH_2O, A=K, Na)Tetragonal cryptomelane was converted to a monoclinic cryptomelane and bixybite by heating at about 700^ﾟC in air. Alkali ions in the part were concentrated in the tunnel and caused the transformation to monoclinic phase accompanying with simulutaneous formation of bixbyite. Structural study in dicated that the Mn^<3+> ions were ordered in the monoclinic cryptomelane.(4) Valence State of Tellurium in BismuthtelluratesValence state of tellurium in the compounds appeared in the pseudo-ternary system Bi_2O_3-Sro-TeO_2 and Bi_2O_3-Pbo-TeO_2 in air was mostly in the state of Te^<4+>. In a superstructure of fluorite, Bi_2SrTeO_7, tellurium ion existed as Te^<6+>.

(1)雅各布石(MnFe_2O_4)-黑斯曼石(Mn_3O_4)体系相平衡图的制作在赤铁矿-磁铁矿氧缓冲液下通过固相反应绘制了雅各布石-黑锰石体系的相图。通过电子探针分析来确定立方相和四方相共存的两相区的组成。热力学方法揭示了立方相中Mn^<2+>、Fe^<2+>、Mn^<3+>、Fe^<3+>等化学成分与金属空位之间的平衡浓度关系。(2)利用高温粉末X射线衍射仪观察软锰矿热分解行为两种热异软锰矿(S)和 (D) 已知； (S)显示约650^ﾟC处的一个吸热峰，(D)显示约相同温度的两个吸热峰。对它们的高温X射线测量表明，(S)在约650^ﾟC时分解并专门转化为方铁锰矿(α-Mn_2O^3)，而(D)除了方铁矿之外还转化为γ-Mn_2O_3和Mn_5O_8。 (D)的热行为可以从(D)中的氧缺陷来解释。 (3)隐锰矿(A_xMn_8O_<16>.nH_2O,A=K,Na)的热转化通过在空气中加热到约700^ﾟC，四方隐锰矿转化为单斜晶系隐锰矿和红铁矿。该部分的碱离子集中在孔道中，引起单斜相转变，同时形成方铁锰矿。结构研究表明，Mn^<3+>离子在单斜晶系锰矿中有序排列。(4)碲酸铋中碲的价态拟三元系Bi_2O_3-Sro-TeO_2和Bi_2O_3-Pbo-TeO_2中出现的化合物中碲的价态在空气中大多呈 Te^<4+>。在萤石的上层结构Bi_2SrTeO_7中，碲离子以Te^6+的形式存在。

项目成果

H.Kudo,H.Miura and Y.Hariya: "Tetragonalーmonoclinic transformation of cryptomelane at high temperature" Miner.J.15. 50-63 (1990)

H.Kudo、H.Miura 和 Y.Hariya：“高温下锰矿的四方单斜转变”Miner.J.15 (1990)。

H. MIURA, H. KUDO, J. H. CHOI AND Y. HARIYA: ""The crystal structure of ramsdellite from Pirika mine"" J. Fac. Sci., Hokkaido Univ., Ser. IV. 22. 611-617 (1990)

H. MIURA、H. KUDO、J. H. CHOI 和 Y. HARIYA：““来自 Pirika 矿的斜方锰矿的晶体结构”J. Fac。

H.Miura,H.Kudo,J.H.Choi and Y.Hariya: "The crystal structure of ramsdellite from Pirika mine" J.Fac.Sci.,Hokkaido Univ.,Ser.IV. 22. 611-617 (1990)

H.Miura、H.Kudo、J.H.Choi 和 Y.Hariya：“来自 Pirika 矿的斜方锰矿的晶体结构”J.Fac.Sci.，北海道大学，Ser.IV。

H.Kudo: "Tetragonalーmonoclinic transformation of cryptomelane at high temperature" Miner.J.15. 50-63 (1990)

H.Kudo：“高温下钾锰矿的四方单斜转变”Miner.J.15（1990）。

T. KIKUCHI, T. HATANO AND H. SAKAI: ""Synthesis of new compounds of the pseudo-ternary system srO-Bi_2O_3-TeO_2 in air"" J. Materials Sci.25. 1285-1288 (1990)

T. KIKUCHI、T. HATANO 和 H. SAKAI：“空气中伪三元体系 srO-Bi_2O_3-TeO_2 新化合物的合成”J. Materials Sci.25。