超化学计量比氧化铀晶体的研究进展

doi:10.15541/jim20200083

摘要/Abstract

摘要： 氧化铀不仅是重要的核材料, 也是潜在的多功能材料。UO₂晶体具有优异的半导体性能和抗辐照能力, 其禁带宽度(1.3 eV)与Si(1.1 eV)相近, 塞贝克系数是常用热电材料BiTe的4倍, 对太阳光的全吸收使其成为高效的太阳能电池材料, 在半导体、太阳能和热电等领域具有巨大的应用潜力。但是UO₂随着环境变化会出现从缺氧到过氧的价态变化(UO_2±_x, x= -0.5~1), 即超化学计量比特性, 给材料制备和性能控制等方面带来很多问题。本文从相图出发, 总结了各种铀氧化物的结构及其稳定性, 重点聚焦UO₂晶体的研究进展。理想化学计量比UO₂被认为是最好的Mott绝缘体, 其电导率是相对稳定的; 超化学计量比氧化铀则具有半导体特性, 其电导率、热导率、扩散系数以及光学性能都与x密切相关。目前, UO₂晶体生长主要采用化学气相输运法(CVT)、冷坩埚法、水热法、升华法、助熔剂法等, 晶体尺寸和质量还不理想, 冷坩埚法和水热法被认为是最有潜力的生长技术。氧化铀单晶生长研究不仅有助于深入了解UO₂材料特性, 也为其在太阳能电池、热电器件以及未来电子学领域的应用提供可能性。

关键词: 氧化铀, 超化学计量比, 晶体生长, 半导体, 热电

Abstract: Uranium dioxide is a potential multi-functional material as well as nuclear rod. It exhibits excellent semiconductor performance and anti-irradiation ability. It has the similar band gap (1.3 eV) of silicon crystal (1.1 eV), its Seebeck coefficient is 4 times of the commercial thermoelectric material BiTe, and it shows higher conversion efficiency of solar cells due to its nearly full absorption. These properties make it great potential applications in the fields of semiconductor, solar energy and thermoelectricity. However, the U atoms in uranium dioxide (UO_2±_x) can vary from -0.5 to 1, which is called hyperstoichiometric characteristics, resulting in some problems in crystal growth and property homogeneity. In this paper, we analyzed the structure and chemical stability of uranium oxides according to U-O phase diagrams, summarized recent research progress on crystal growth and physical properties of UO₂ crystals. UO₂ is an ideal Mott insulator with a stable electric conductivity, while the hyperstoichiometric UO_2±_x crystals are semiconductors, and their physical properties, including electric conductivity, thermal conductivity and diffusion coefficient, and optical properties, are closely related to x. So far, UO₂ crystals have grown via several methods, such as chemical vapor transport (CVT), sublimation, skull melting, hydrothermal and flux. The skull melting and hydrothermal techniques are expected to improve crystal dimensions and quality in future. The growth of UO₂ crystals is expected to enhance the understanding of the material and provide the possibility of great potential applications in solar cells, thermoelectric devices and future electronics.

Key words: UO₂, stoichiometric, crystal growth, semiconductor, thermoelectricity

中图分类号:

TQ174

徐家跃, 李志超, 潘芸芳, 周鼎, 温丰, 马文军. 超化学计量比氧化铀晶体的研究进展[J]. 无机材料学报, 2020, 35(11): 1183-1192.

XU Jiayue, LI Zhichao, PAN Yunfang, ZHOU Ding, WEN Feng, MA Wenjun. Research Progress of Hyperstoichiometric UO₂ Crystals[J]. Journal of Inorganic Materials, 2020, 35(11): 1183-1192.

参考文献

[1] 赵紫原. 新兴经济体引领世界核电发展. 中国能源报, 2019年04月08日, 第12版.
[2] 李冠兴, 武胜. 核燃料. 北京:化学工业出版社, 2012.
[3] SARI C, BENEDICT U, BLANK H.A study of the ternary system UO₂-PuO₂-Pu₂O₃. Journal of Nuclear Materials, 1970, 35(3): 267-277.
[4] ROLSTON K.Uranium crystals could reveal future of nuclear fuel. http://phys.org/news/2013-06-uranium-crystals-reveal-future-nuclear.html.
[5] SKINNER B L, BENMORE C J, WEBER R K J,et al. Molten uranium dioxide structure and dynamics. Science, 2014, 346: 984-987.
[6] ALEXANDRA NAVROTSKY.Taking the measure of molten uranium oxide.Science, 2014, 346: 916-917.
[7] MEEK T T, VON ROEDERN B.Semiconductor devices fabricated from actinide oxides.Vacuum, 2008, 83(1): 226-228.
[8] MEEK T, HU M, HAIRE M J.Semiconductive properties of uranium oxides.Ornl, 2001, 10(6): 10-18.
[9] LIERDE W V.The preparation of uranium oxde single crystals by sublimation.Journal of Nuclear Materials, 1962, 5(2): 250-253.
[10] CHAPMAN A T, CLARK G W.Growth of UO₂, single crystals using the floating-zone technique.Journal of the American Ceramic Society, 1965, 48(9): 494-495.
[11] YOUNG C, PETROSKY J, MANN J M,et al. The work function of hydrothermally synthesized UO₂ and the implications for semiconductor device fabrication. Physica Status Solidi-Rapid Research Letters, 2016, 10(9): 687-690.
[12] ROBINS R G.Uranium dioxide single crystals by electrodeposition.Journal of Nuclear Materials, 1961, 3(3): 294-301.
[13] KAVAZAURI R, POKROVSKIY S A, BARANOV V G, et al.Thermal Properties of Nonstoichiometry Uranium Dioxide. IOP Conference Series: Materials Science and Engineering. IOP Publishing, 2016, 130(1): 012025.
[14] KRUSCHWITZ C A, MUKHOPADHYAY S, SCHWELLENBACH D,et al. Semiconductor neutron detectors using depleted uranium oxide hard X-ray, gamma-ray, and neutron detector physics XVI. International Society for Optics and Photonics, 2014, 9213: 92130C.
[15] KIM Y S.A thermodynamic evaluation of the U-O system from UO₂ to U₃O₈.Journal of Nuclear Materials, 2000, 279(2/3): 173-180.
[16] KVASHNINA K O, BUTORIN S M, MARTIN P,et al. Chemical state of complex uranium oxides. Physical Review Letters, 2013, 111(25): 253002.
[17] WHITE J T, NELSON A T.Thermal conductivity of UO₂+_x and U₄O₉-_y. Journal of Nuclear Materials, 2013, 443(1/2/3): 342-350.
[18] MOLINARI M, BRINCAT N A, ALLEN G C, et al. Structure and properties of some layered U₂O₅ phases: a density functional theory study. Inorganic Chemistry, 2017, 56(8): 4468-4473.
[19] COLMENERO F, BONALES L J, COBOS J, et al. Density functional theory study of the thermodynamic and Raman vibrational properties of γ-UO₃ polymorph. The Journal of Physical Chemistry C, 2017, 121(27): 14507-14516.
[20] HIERNAUT J P, HYLAND G J, RONCHI C.Premelting transition in uranium dioxide.International Journal of Thermophysics, 1993, 14(3): 609-612.
[21] HIGGS J D, THOMPSON W T, LEWIS B J, et al. Kinetics of precipitation of U₄O₉ from hyperstoichiometric UO₂+_x. Journal of Nuclear Materials, 2007, 366(3): 297-305.
[22] OLSEN A M, SCHWERDT I J, RICHARDS B, et al. Quantification of high temperature oxidation of U₃O₈ and UO₂. Journal of Nuclear Materials, 2018, 508: 574-582.
[23] JAVED N A.Thermodynamic study of hypostoichiometric urania.Journal of Nuclear Materials, 1972, 43(3): 219-224.
[24] LATTA R E, FRYXELL R E.Determinaion of solidus-liquidus temperatures in the UO₂+_x system(-0.50<x<0.20). Journal of Nuclear Materials, 1970, 35(2): 195-210.
[25] KIM K C, OLANDER D R.Oxygen diffusion in UO₂-_x. Journal of Nuclear Materials, 1981, 102(1/2): 192-199.
[26] HAYWARD P J, EVANS D G, TAYLOR P, et al. Oxidation of uranium in argon-25% oxygen at 190-610 ℃. Journal of Nuclear Materials, 1992, 187(3): 215-222.
[27] 白新德, 核材料科学与工程:核材料化学. 北京: 化学工业出版社, 2007: 305-309.
[28] BLANK H, RONCHI C.Electron diffraction of U₄O₉.Acta Crystallographica Section A: Crystal Physics, Diffraction, Theoretical and General Crystallography, 1968, 24(6): 657-666.
[29] KEIJI N.Phase transitions of U₄O₉. Journal of Nuclear Materials, 1974, 51(1): 126-135.
[30] VAN LIERDE W, PELSMAEKERS J, LECOCQ-ROBERT A.On the phase limits of U₄O₉.Journal of Nuclear Materials,1970, 37(3): 276-285.
[31] TEIXEIRA S R, IMAKUMA K.High temperature X-ray diffraction study of the U₄O₉ formation on UO₂ sintered plates.Journal of Nuclear Materials, 1991, 178(1): 33-39.
[32] HOEKSTRA H R, SANTORO A, SIEGEL S.The low temperature oxidation of UO₂ and U₄O₉. Journal of Inorganic and Nuclear Chemistry, 1961, 18: 166-178.
[33] ELORRIETA J M, BONALES L J, RODRIGUEZ-VILLAGRA N,et al. A detailed Raman and X-ray study of UO₂+_x oxides and related structure transitions. Physical Chemistry Chemical Physics, 2016, 18(40): 28209-28216.
[34] DESGRANGES L, BALDINOZZI G, ROUSSEAU G, et al. Neutron diffraction study of the in situ oxidation of UO₂. Inorganic Chemistry, 2009, 48(16): 7585-7592.
[35] SIEGEL S.The crystal structure of trigonal U₃O₈.Acta Crystallographica, 1955, 8(10): 617-619.
[36] 张延志, 汪小琳, 赖新春, 等. 不同温度下U₃O₈结构的XRD研究. 核化学与放射化学, 2003, 25(2): 69-73.
[37] LOOPSTRA B O.The phase transition inα-U₃O₈ at 210 ℃. Journal of Applied Crystallography, 1970, 3(2): 94-96.
[38] LOOPSTRA B O.The structure ofβ-U₃O₈. Acta Crystallographica Section B: Structural Crystallography and Crystal Chemistry, 1970, 26(5): 656-657.
[39] OLANDER D R.Oxidation of UO₂ by high-pressure steam. Nuclear technology, 1986, 74(2): 215-217.
[40] ZHANG F X, LANG M, WANG J W, et al. High-pressure U₃O₈ with the fluorite-type structure. Journal of Solid State Chemistry, 2014, 213: 110-115.
[41] HOEKSTRA H R, SIEGEL S, GALLAGHER F X.The uranium- oxygen system at high pressure. Journal of Inorganic & Nuclear Chemistry, 1970, 32(10): 3237-3248.
[42] KOVBA L M, KOMAREVTSEVA N I, KUZ'MICHEVA E U. On the crystal structures of U₁₃O₃₄ and delta-U₂O₅.Radiokhimiya, 1979, 21(5): 754-757.
[43] LOOPSTRA B O, CORDFUNKE E H P. On the structure ofα-UO₃. Recueil des Travaux Chimiques des Pays-Bas, 1966, 85(2): 135-142.
[44] LOOPSTRA B O, TAYLOR J C, WAUGH A B.Neutron powder profile studies of the gamma uranium trioxide phases.Journal of Solid State Chemistry, 1977, 20(1): 9-19.
[45] BRINCAT N A, PARKER S C, MOLINARI M,et al. Ab initio investigation of the UO₃ polymorphs: structural properties and thermodynamic stability. Inorganic Chemistry, 2014, 53(23): 12253-12264.
[46] SCHOENES J.Optical properties and electronic structure of UO₂.Journal of Applied Physics, 1978, 49(3): 1463-1465.
[47] SHI H, CHU M, ZHANG P.Optical properties of UO₂ and PuO₂.Journal of Nuclear Materials, 2010, 400(2): 151-156.
[48] SINGH S, GUPTA S K, SONVANE Y,et al. Ab-initio calculation on electronic and optical properties of ThO₂, UO₂ and PuO₂. Journal of Nuclear Materials, 2018, 511: 128-133.
[49] CHEN Q, LAI X, BAI B,et al. Structural characterization and optical properties of UO₂ thin films by magnetron sputtering. Applied Surface Science, 2010, 256(10): 3047-3050.
[50] 陈秋云, 赖新春, 白彬, 等. UO₂薄膜制备和光学常数及厚度测定. 原子能科学技术, 2010, 44(9): 1126-1130.
[51] 陈秋云, 赖新春, 王小英, 等. UO₂的电子结构及光学性质的第一性原理研究. 物理学报, 2010, 59(7): 4945-4949.
[52] DEVETTER B M, MYERS T L, CANNON B D,et al. Optical and chemical characterization of uranium dioxide (UO₂) and uraninite mineral: calculation of the fundamental optical constants. The Journal of Physical Chemistry A, 2018, 122(35): 7062-7070.
[53] ELORRIETA J M, BONALES L J, BAONZA V G, et al. Temperature dependence of the Raman spectrum of UO₂. Journal of Nuclear Materials, 2018, 503: 191-194.
[54] MISKOWIEC A, NIEDZIELA J L, SPANO T L, et al. Additional complexity in the Raman spectra of U₃O₈. Journal of Nuclear Materials, 2019, 527: 151790.
[55] LIVNEH T, STERER E.Effect of pressure on the resonant multiphonon Raman scattering in UO₂.Phys. Rev. B, 2006, 73: 085118-085119.
[56] 吕俊波, 李赣, 郭淑兰. 非理想化学计量比氧化铀的拉曼和红外光谱. 光谱学与光谱分析, 2014, 34(2): 405-409.
[57] WINTER P W.The electronic transport properties of UO₂.Journal of Nuclear Materials, 1989, 161(1): 38-43.
[58] MEEK T T, VON ROEDERN B, CLEM P G,et al. Some optical properties of intrinsic and doped UO₂ thin films. Materials Letters, 2005, 59(8/9): 1085-1088.
[59] VON ROEDERN B, MEEK T T, HAIRE M J.Some Electrical Properties of Ion-implanted Urania--Part II. National Renewable Energy Lab., Golden, CO.(US), 2003.
[60] SZE S M.Energy Bands and Carrier Concentration. Semiconductor Devices, Physics and Technology. New York: John Wiley and Sons, 1985: 18-19.
[61] KEIM R, KELLER C.U Uranium: Supplement Volume C5 Uranium Dioxide, UO₂, Physical Properties. Electrochemical Behavior. Springer Science & Business Media, 2013.
[62] ARONSON S, RULLI J E, SCHANER B E.Electrical properties of nonstoichiometric uranium dioxide.The Journal of Chemical Physics, 1961, 35(4): 1382-1388.
[63] HAMPTON R N, SAUNDERS G A, STONEHAM A M.The frequency dependent response of the electrical impedance of UO₂. Journal of Nuclear Materials, 1986, 139(3): 185-190.
[64] RUELLO P, PETOT-ERVAS G, PETOT C,et al. Electrical conductivity and thermoelectric power of uranium dioxide. Journal of the American Ceramic Society, 2005, 88(3): 604-611.
[65] DUGAN C L, PETERSON G G, MOCK A, et al. Electrical and material properties of hydrothermally grown single crystal (111) UO₂. The European Physical Journal B, 2018, 91(4): 67.
[66] DJERASSI H, SORRIAUX A P.Thermoelectric properties of the uranium oxide U₃O₈.Journal of Applied Physics, 1972, 43(3): 1275-1276.
[67] AN Y Q, TAYLOR A J, CONRADSON S D, et al. Ultrafast hopping dynamics of 5f, electrons in the Mott-insulator UO₂, studied by femtosecond pump-probe spectroscopy. Physical Review Letters, 2011, 106(20): 49-80.
[68] YOUNG R A.Model for the electronic contribution to the thermal and transport properties of ThO₂, UO₂, and PuO₂ in the solid and liquid phases. Journal of Nuclear Materials, 1979, 87(2/3): 283-296.
[69] HARDING J H, MARTIN D G.A recommendation for the thermal conductivity of UO₂.Journal of Nuclear Materials, 1989, 166(3): 223-226.
[70] ARING K, SIEVERS A J.Thermal conductivity and far-infrared absorption of UO₂. Journal of Applied Physics, 1967, 38(3): 1496-1498.
[71] MOORE J P, MCELROY D L.Thermal conductivity of nearly stoichiometric single-crystal and polycrystalline UO₂. Journal of the American Ceramic Society, 1971, 54(1): 40-46.
[72] GOFRYK K, DU S, STANEK C R,et al. Anisotropic thermal conductivity in uranium dioxide. Nature Communications, 2014, 5(4551): 1-7.
[73] RONCHI C, SHEINDLIN M, MUSELLA M,et al. Thermal conductivity of uranium dioxide up to 2900 K from simultaneous measurement of the heat capacity and thermal diffusivity. Journal of Applied Physics, 1999, 85(2): 776-789.
[74] VLAHOVIC L, STAICU D, KÜST A,et al. Thermal diffusivity of UO₂ up to the melting point. Journal of Nuclear Materials, 2018, 499: 504-511.
[75] CHAPMAN A T, CLARK G W.Growth of UO₂, single crystals using the floating-zone technique.Journal of the American Ceramic Society, 1965, 48(9): 494-495.
[76] HERRICK C C, BEHRENS R G.Growth of large uraninite and thorianite single crystal from the melt using a cold-crucible technique. Journal of Crystal Growth, 1981, 51(2): 183-189.
[77] BURGETT E, DEO C, PHILLPOT S.Fuel Performance Experiments on the Atomistic Level, Studying Fuel Through Engineered Single Crystal UO₂. Battelle Energy Alliance, LLC, Idaho Falls, ID(United States), 2015.
[78] BUGARIS DANIEL E, ZUR LOYE HANS-CONRAD. Materials discovery by flux crystal growth: quaternary and higher order oxides.Angew. Chem. Int. Ed., 2012, 51: 3780-3811.
[79] MANN M, HUNT E, YOUNG C, et al. Hydrothermal Growth and Characterization of UO₂ Single Crystals for Neutron Radiation Detection (Conference Presentation)//Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XVIII. International Society for Optics and Photonics, 2016, 9968: 99680R.
[80] MANN J M, KOLIS J, HUNT E.Uranium Dioxide Based Crystals and Methods of Fabrication. US. 20160348267. 2016.
[81] SINGH R N, COBLE R L.Growth of uranium dioxide single crystals by chemical vapor deposition. Journal of Crystal Growth, 1974, 21(2): 261-266.
FAILE S P.Growth of uranium dioxide crystals using tellurium tetrachloride and argon. Journal of Crystal Growth, 1978, 43(1): 133-134.