Structural analysis and physical properties of High-Pressure and Low-Temperature Phases of Solid Oxygen

固氧高压低温相的结构分析和物理性质

• 批准号: 12640321
• 负责人: AKAHAMA Yuichi
• 金额: $ 2.3万
• 依托单位: Himeji Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12640321/
• 关键词: solid oxygen; insulator-metal transition; molecular dissociation; phase transition; molecular magnetism; high pressure; x-ray diffraction; infrared absorption

The phase transition of solid oxygen has been investigated at low-temperatures of 19 K, 180 K and 240 K and at high-pressures of up to 12 Gpa using monochromatic synchrotron x-ray diffraction techniques, and the phase relation among α-,β-δ-, and ε-0_2 has been revealed, based on the structural data. The monoclinic α-0_2 phase at 19K, with increasing pressure, directly transformed to theε-0_2 phase at 7.6 Gpa. The α-δ phase boundary was located on a higher temperature region than 240 K and the α-0_2 phase was stable over a wide pressure and temperature range. The b/a ratio of the lattice constants at 19 K exhibited a monotonic increase with pressure and reached 0.708 at 7.6 GPa, while it abruptly decreased to 0.690 by the α-ε transition. From the anisotropy of compressibility, the existence of a collinear antiferromagnetic order in the α-0_2 phase was confirmed at pressure up to 7.2 Gpa. The equation of state of the α-0_2 phase at 19 K has also been determined.The structure and lattice … More compression of β-0_2 phase have been studied at 277 K and 300 K. The pressure dependence of lattice constants, a and c, obtained from a powder indicated an anisotropic compressibility, a is almost seven times as compressible as c.This large linear compressibility of a may be attributed to the antiferromagnetic interaction in the basal plane. An analogy of the lattice deformation between the α-δ and α-β phase transitions was also suggestive of the magnetic order in theδ phase.The structure of the metallic ζpnase above 100 Gpa was determined to be a monoclinic lattice (SG : P2/m) with Z=2. This lattice consisted of 0_2 molecules. Therefore, this phase was concluded to be molecular semi metallic.The single crystal growth of β, δ, and ε-0_2 phases and the structure analyses of these crystals were carried out at room temperature. The sample quality was very good and the full width at half maximum was about 0.005^o. The data collection was carried out by several methods. It is found that the thermal parameter in basal planeβ_<11>, was considerably large. Less

用单色同步辐射X射线衍射技术研究了固体氧在19 K、180 K和240 K低温和12 GPa高压下的相变，并根据结构数据揭示了α-、β-δ-和ε-O_2之间的相关系。19 K时的单斜α-0_2相在7.6Gpa时直接转变为ε-0_2相。α-δ相界位于240 K以上的高温区，α-0_2相在较宽的温度和压力范围内稳定。在19 K时，晶格常数的B/a比值随压力的增加而单调增加，在7.6 GPa时达到0.708，而在α-ε转变时突然下降到0.690。从压缩性的各向异性来看，在7.2Gpa的压力下，α-0_2相存在共线反铁磁有序。确定了α-0_2相在19 K时的状态方程，并对α-0_2相的结构和晶格进行了分析 ...更多信息 在277 K和300 K下研究了β-0_2相的压缩。从粉末中获得的晶格常数，a和c的压力依赖性表明各向异性的可压缩性，a几乎是7倍的可压缩性为c。这种大的线性可压缩性的a可能是由于在基面的反铁磁相互作用。α-δ相变和α-β相变之间的晶格变形的相似性也暗示了δ相中的磁序.在100 Gpa以上的金属铌酸盐的结构被确定为单斜晶格（SG：P2/m），Z=2.这种晶格由0_2分子组成。在室温下进行了β、δ和ε-0_2相的单晶生长和结构分析。样品质量非常好，半高宽约为0.005 μ m。通过几种方法进行数据收集。结果表明，基面的热参数β_<11>i相当大。少

项目成果

Y.Akahama et al.: "Eguation of State of Bismuth to 220GPa and Comparison of gold and Platinum Pressure Scales to 145Gpa"J.Appl.Phys.. (in press). (2002)

Y.Akahama 等人：“铋态至 220GPa 的计算以及金和铂压力标度至 145Gpa 的比较”J.Appl.Phys..（出版中）。

Y. Akahama, M. Kobayashi and H. Kawamura: "Simple Cubic-Simple Hexagonal Transition in Phosphorus under Pressure"Phys. Rev. B. 59. 8520-25 (1999)

Y. Akahama、M. Kobayashi 和 H. Kawamura：“压力下磷的简单立方-简单六方转变”Phys。

Y. Akahama, H. Kawamura, S. Carlson, T. Le Bihan and D. Hausermann: "Structural Stability and Equation of State of Simple-Hexagonal Phosphorus to 280 Gpa: Phase Transition at 262 Gpa"Phys. Rev.B. 61. 3139-42 (2000)

Y. Akahama、H. Kawamura、S. Carlson、T. Le Bihan 和 D. Hausermann：“简单六方磷至 280 Gpa 的结构稳定性和状态方程：262 Gpa 下的相变”Phys。

H. Kawamura, Y. Akahama, S. Umemoto, T. Takemura, Y. Ohishi, and 0. Shimomura: "X-ray powder diffraction from solid deuterium"Solid State Commun. 119. 29-32 (2001)

H. Kawamura、Y. Akahama、S. Umemoto、T. Takemura、Y. Ohishi 和 0. Shimomura：“固体氘的 X 射线粉末衍射”Solid State Commun。

Y. Akahama, and H. Kawamura: "Optical and Electrical Studies on Band-Overlapped Metallization of Narrow-Gap Semiconductor of Black Phosphorus with Layered Structure"Rhys. Stat. Sol. (B). 223. 349-353 (2001)

Y. Akahama 和 H. Kawamura：“层状结构黑磷窄带隙半导体能带重叠金属化的光电研究”Rhys。