线性正磁电阻材料硒化银的制备工艺及性能研究
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摘要
自掺杂非化学计量比的硒化银和碲化银材料(简称硫族银化物材料)在较宽的温度范围(1K-300K)和超宽的磁场范围(1mT~60T)具有大的正线性磁电阻效应(LMR),且脉冲磁场直到60T,其LMR仍未达到饱和,这种奇异的线性磁电阻效应因其巨大的应用价值已引起了研究者的广泛关注。
本文首次采用两步合成法成功地制备出完全化学计量比及非化学计量比的硒化银( Ag 2+δSe(δ≥0))晶体,分析了硒化银晶体的物相、微结构及形貌,探究了两步合成法制备硒化银晶体的最佳工艺条件,并研究了晶体的物理性能。
本文通过改变化学反应方程式中Se的配比,利用室温合成法得到含不同过量银的硒化银纳米颗粒,然后通过固相合成法制备出晶体。XRD和SEM分析结果表明,室温合成法中,反应时间为10h时,可得到高纯的正交α相硒化银纳米颗粒;固相合成法中,温度为500℃时,可烧结出结晶完全的硒化银晶体,流通的氩气氛烧结及粉体预热处理工艺均可有效提高晶体的致密度。
采用XRD和SEM对制备出的硒化银晶体进行微观性能的研究,结果表明,随着Se配比的降低(≥75%), Ag 2+δSe晶体中过量银的含量逐渐增多,其存在形式也由小微粒逐渐转变为纳米级的团聚体,同时,硒化银晶体的晶粒尺寸也逐渐减小。此外, Ag 2+δSe晶体中的过量银呈现出略显规则的链条式排列镶嵌在Ag 2S e母体中,链条的方向也基本一致。
最后,采用多种测试手段,对硒化银晶体的物理性能进行了研究。结果表明,硒化银晶体为n型半导体,其禁带宽度约1.56~1.97eV,为窄禁带半导体,其中,非化学计量比硒化银的禁带宽度值略高;晶体的电阻率随温度的升高(105K~293K),先增大后减小,与杂质半导体的阻温特性一致;晶体具有正线性磁电阻效应,其中室温及1.73T下的磁电阻值可达10%,并且Se配比越低(≥75%), Ag 2+δSe晶体的磁电阻效应越明显,其临界磁场值越小。
Self-doped nonstoichiometric silver chalcogenides have attracted lots of attention due to their unusually large, positive and linear magnetoresistance effect (LMR), which exhibits a linear dependence on magnetic field in a wide temperature range (1K-300K) and wide range of magnetic field (1mT ~ 60T). Especially, LMR has no saturation at the high magnetic field up to 60 T.
In this thesis, both stoichiometric and nonstoichiometric silver selenide ( Ag 2+δSe(δ≥0)) crystals have been successfully synthesized by the two-step method for the first time. The structure and morphology of the samples were analyzed, the optimal preparation conditiones were investigated, and their physical properties were studied.
Firstly, selenium proportion in chemical equation was changed and silver selenide nanoparticles with different silver excess ( Ag 2+δSe(δ≥0))were synthesized by room temperature method, and then were sintered into crystals by solid state method. The results of XRD and SEM indicated that 10h is the optimal reaction time with the result of high-purityα? Ag 2 +δSe nanoparticles and 500℃is the best sintering temperature with the result of completed- crystallized Ag 2 +δSe crystals. Moreover, the dense of crystals were improved when sintered in flowing argon of crystals as well as treated to the nanoparticles before sintered.
Secondly, X-ray diffraction and scanning electron microscopy were used to characterize the microstructure of Ag 2 +δSecrystals. The results showed that, with the reducing Se in mixture ratio, the size of crystal reduced and there were more excess silver which exists as atoms or clusters and arranged chainlike in the silver selenide matrix.
Moreover, the physical properties of Ag 2 +δSewere analyzed by using various test methods. The results indicated that Ag 2 +δSe crystals were n-type small-gap semiconductors with bandgap energies of 1.56~1.97eV, among samples, the bandgap of nonstoichiometric Ag 2 +δSe was slightly higher than those of Ag2Se; with increased temperature, the electric conductivity of crystals increased at first and arrived at a maximum, then reduced rapidly, which is coordinated with the conductivity- temperature proper of doped semiconductor; a positive and linear MR effect was discovered surprisingly with a large MR effect up to 10% at room temperature and magnetic fields of 1.73T. Also, the MR effect of Ag 2 +δSe crystals was improved and the transition field from OMR to LMR was reduced with reduced proportion of Se in mixture ratio(≥75%).
本文首次采用两步合成法成功地制备出完全化学计量比及非化学计量比的硒化银( Ag 2+δSe(δ≥0))晶体,分析了硒化银晶体的物相、微结构及形貌,探究了两步合成法制备硒化银晶体的最佳工艺条件,并研究了晶体的物理性能。
本文通过改变化学反应方程式中Se的配比,利用室温合成法得到含不同过量银的硒化银纳米颗粒,然后通过固相合成法制备出晶体。XRD和SEM分析结果表明,室温合成法中,反应时间为10h时,可得到高纯的正交α相硒化银纳米颗粒;固相合成法中,温度为500℃时,可烧结出结晶完全的硒化银晶体,流通的氩气氛烧结及粉体预热处理工艺均可有效提高晶体的致密度。
采用XRD和SEM对制备出的硒化银晶体进行微观性能的研究,结果表明,随着Se配比的降低(≥75%), Ag 2+δSe晶体中过量银的含量逐渐增多,其存在形式也由小微粒逐渐转变为纳米级的团聚体,同时,硒化银晶体的晶粒尺寸也逐渐减小。此外, Ag 2+δSe晶体中的过量银呈现出略显规则的链条式排列镶嵌在Ag 2S e母体中,链条的方向也基本一致。
最后,采用多种测试手段,对硒化银晶体的物理性能进行了研究。结果表明,硒化银晶体为n型半导体,其禁带宽度约1.56~1.97eV,为窄禁带半导体,其中,非化学计量比硒化银的禁带宽度值略高;晶体的电阻率随温度的升高(105K~293K),先增大后减小,与杂质半导体的阻温特性一致;晶体具有正线性磁电阻效应,其中室温及1.73T下的磁电阻值可达10%,并且Se配比越低(≥75%), Ag 2+δSe晶体的磁电阻效应越明显,其临界磁场值越小。
Self-doped nonstoichiometric silver chalcogenides have attracted lots of attention due to their unusually large, positive and linear magnetoresistance effect (LMR), which exhibits a linear dependence on magnetic field in a wide temperature range (1K-300K) and wide range of magnetic field (1mT ~ 60T). Especially, LMR has no saturation at the high magnetic field up to 60 T.
In this thesis, both stoichiometric and nonstoichiometric silver selenide ( Ag 2+δSe(δ≥0)) crystals have been successfully synthesized by the two-step method for the first time. The structure and morphology of the samples were analyzed, the optimal preparation conditiones were investigated, and their physical properties were studied.
Firstly, selenium proportion in chemical equation was changed and silver selenide nanoparticles with different silver excess ( Ag 2+δSe(δ≥0))were synthesized by room temperature method, and then were sintered into crystals by solid state method. The results of XRD and SEM indicated that 10h is the optimal reaction time with the result of high-purityα? Ag 2 +δSe nanoparticles and 500℃is the best sintering temperature with the result of completed- crystallized Ag 2 +δSe crystals. Moreover, the dense of crystals were improved when sintered in flowing argon of crystals as well as treated to the nanoparticles before sintered.
Secondly, X-ray diffraction and scanning electron microscopy were used to characterize the microstructure of Ag 2 +δSecrystals. The results showed that, with the reducing Se in mixture ratio, the size of crystal reduced and there were more excess silver which exists as atoms or clusters and arranged chainlike in the silver selenide matrix.
Moreover, the physical properties of Ag 2 +δSewere analyzed by using various test methods. The results indicated that Ag 2 +δSe crystals were n-type small-gap semiconductors with bandgap energies of 1.56~1.97eV, among samples, the bandgap of nonstoichiometric Ag 2 +δSe was slightly higher than those of Ag2Se; with increased temperature, the electric conductivity of crystals increased at first and arrived at a maximum, then reduced rapidly, which is coordinated with the conductivity- temperature proper of doped semiconductor; a positive and linear MR effect was discovered surprisingly with a large MR effect up to 10% at room temperature and magnetic fields of 1.73T. Also, the MR effect of Ag 2 +δSe crystals was improved and the transition field from OMR to LMR was reduced with reduced proportion of Se in mixture ratio(≥75%).
引文
[1] W. Thomson, Effects of magnetization on the electric conductivity of nickel and of iron. Proc.Roy.Soc. 1857, 8:546-550
[2] R. P. Hunt, Magnetoresistive Read Out Transducer. IEEE Trans, Magn, 1971, 7:150
[3] M. N. Baibich, J. M. Broto, A. Fert et al, Giant Magnetoresistance of (001)Fe/(001)Cr Magnetic Super- latices. Phys.Rev.Let. 1988, 61(21):2472-2475
[4] B. Dieny, V. S. Speriosu, S. P. Parkin et al, Giant Magnetoresistance in Soft Ferromagnetic Multilayers. Phys.Rev. B, 1991, 43(1):1297
[5] S. Jin, T. H. Tiefel, M. McCormack et al, Thousandfold Change in Resistivity in Magnetoresistive La-Ca-Mn-O Films. Science, 1994, 264:413
[6] T. Miyazaki and N. Tezuka, Giant Magnetic Tunneling Effect in Fe/A1203/Fe Junction. Magn. Mater, 1995, 139:L231-L234
[7] P. A. Penz and R. Bowers, Strain-Dependent Magnetoresistance of Potassium. Phys. Rev. 1968, 172:991
[8] B K Jones, Strain-Dependent Magnetoresistance of Sodium and Potassium. Phys. Rev.1969,179:637
[9] J. S. Lass, Induced torque in an ellipsoid. Torque anisotropy in potassium. J. Phys. C: Solid State Phys. 1970, 3:1926
[10] H. Taub, R. L. Schmidt, B. Maxwell et al, Study of the Transverse Magnetoresistance of Polycrystalline Potassium. Phys. Rev. B, 1971, 4:1134
[11] A. M. Simpson, Magnetoresistance of potassium. J. Phys. F: Met. Phys. 1973, 3:1471
[12] R S Newrock, B W Maxwell, Transverse thermal magnetoresistance of potassium. J. Low Temp. Phys. 1976, 23:119
[13] F R Fickett, Magnetoresistance of Very Pure Polycrystalline Aluminum. Phys. Rev. B, 1971, 3:1941
[14] J C Garland and R Bowers, High-Field Galvanomagnetic Properties of Indium. Phys.Rev. 1969, 188:1121
[15] J E Huffman, M L Snodgrass and F J Biatt, Magnetoresistance of copper, gold, and indium. Phys. Rev. B, 1981, 23:483
[16] W. Schneider, H. Bruhms and K. Hubner, Geometric manipulation of the high-field linear magnetoresistance. J. Phys. Chem. Solids, 1980, 41:313
[17] R. S. Allgaier, J. B. Restorff and Bland Houston, Weak- and strong-field magnetoresistance in (111)-oriented n-type PbTe epitaxial films between 1.8 and 300 K. J. Appl. Phys. 1982, 53(4):3110
[18] J. W. Gallagher and W. F. Love, Transverse Magnetoresistance in n-Type Germanium. Phys. Rev. 1967, 161:793
[19] H. Weiss, Structure and Applications of Galvanomagnetic Devices, New York: Pergamon Press, 1969
[20] R. Xu, A. Husmann, T. F. Rosenbaum et al, Large Magnetoresistance in non-magnetic silver chalcogenides. Nature, 1997, 390(6):57-60
[21] M Kobayashi, Review on structural and dynamical properties of silver chalcogenides. Solid State Ionics, 1990, 39(3-4):212-149
[22] A. J. Frueh, The crystallography of silver sulfide, Ag2S. Jr. Z. Krist. 1959, 112:44
[23] P. Junod and A. Helv, Electrical properties of Ag2Se. Phys. Acta. 1957, 30:470
[24] K. M. Kulinowski, Peng Jiang, H. Vaswani et al, Porous Metals from Colloidal Templates. 2000,12(11): 833-838
[25]萨拉蒙( M. B. Salamon) ,快离子导体物理,北京:科学出版社,1984,16-17
[26] F. Shimojo and H. Okazaki, Boundary Condition Effect in MD Simulation: A Case of theα→βPhase Transition in Superonic Conductor Ag2Se. J. Phys. Soc. Jpn, 1993, 62(1):179-182
[27] K. L. Lewis, X. Zhang, X. F. Qian et al, Ultrafine Powder of Silver Suulfide Semiconductor Prepared in Alcohol Soloution. Mater. Res. Bull. 1998,33(7):1083-1086
[28] K. L. Lewis, A. M. Pitt, P. Wyatt-Davies et al, Crystal gazing into the future of optical coatings. Mater. Res. Soc. Symp. Proc. 1994, 374:105
[29] H. S. Schnyders, M. L. Saboungi, T. F. Rosenbaum, Magnetoresistance in n- and p-type Ag2Te: Mechanisms and applications. Appl. Phys. Lett.2000, 76:13
[30] A. Husmann, J. B. Betts, G. S. Boebinger et al, Megagauss sensors. Nature, 2002, 417 (23):421-424
[31] G Beck, J Janek, Positive and negative magnetoresistance in the system silver–selenium. Physica B, 2001, 086:308-310
[32] G Beck, C Korte, J Janek et al, The magnetoresistance of homogeneous and heterogeneous silver-rich silver selenide. J. Appl. Phys. 2004, 96:5619
[33] J. Janek, B. Mogwitz, G. Beck et al, The magnetoresistance of metal-rich Ag2+xSe-A prototype nanoscale metal/semiconductor dispersion?. Progress in Solid State Chemistry, 2004,32:179-205
[34] G. Beck and J. Janek, Negative and linear positive magnetoresistance effect in silver-rich silver selenide. Solid State Sciences, 2008, 10:776-789
[35] M. von Kreutzbruck, B. Mogwitz,F. Gruhl et al, Magnetroresistance in Ag2+δSe with high silver excess. Appl. Phys. Lett., 2005,86:072102
[36] B Mogwitz, C Korte, J Janek et al, Preparation and magnetoresistance of Ag2+xSe thin films deposited via pulsed laser deposition. J. Appl. Phys., 2007,101:043510
[37] C. N. Rao and A. K. Cheetham, Science and technology of nanomaterials: current status and future prospects. J. Mater. Chem. 2001, 11:2887-2894
[38] H. Toyoji and Y. Hiroshi, Jpn. Kokai Tokyo Kaho JP 02, 1990, 173:622
[39] G. Henshaw, I. P. Parkin, G. Shaw et al, Convenient, Low-energy Synthesis of Metalsulfides and Selenides; PBE, AG2E, ZNE, CDE (E = S, SE). Chem.Comm. 1996, 10:1095-1096
[40] G. Henshaw, I. P. Parkin, G. Shaw et al, Convenient, room-temperature liquidammonia routes to metal chalcogenides. J.Chem.Soc.DaltonTrans. 1997, 2:231-236
[41] V. Dusastre, B. Omar, I. P. Parkin et al, Convenient, room-temperature, amine-assisted routes to metal sulfides, selenides and tellurides. J.Chem.Soc.DaltonTrans. 1997, 19:3505-3508
[42] G. Henshaw, I. P. Parkin and G. Shaw et al, Elemental, liquid ammonia facilitated routed to zinc, cadmium, mercury copper, silver and lead telluride. J. Mater. Sci. Lett. 1996, 15(20):1741-1742
[43] O. Akira, Jpn. Kokai Tokyo Kaho JP61, 1986, 222:910
[44] T. Ohtani, M. Motoki, K. Koh et al, Synthesis of binary copper chalcogenides by mechanical alloying. Mater.Res.Bull. 30(12):1495-1504
[45] T. Ohtani, K. Maruyama and K. Ohshima, Synthesis of copper, silver, and samarium chalcogenides by mechanical alloying. Mater.Res.Bull. 1997, 32(3):343-350
[46] W. Z. Wang, Y. Geng, P. Yan et al, A Novel Mild Route to Nanocrystalline Selenides at Room Temperature. J.Am.Cho.Soc. 1999, 121(16):4062-4063
[47] W. Z. Wang, P. Yan, F. Y. Liu et al, Preparation and characterization of nanocrystalline Cu2–xSe by a novel solvothermal pathway. J. Mater.Chem. 1998, 11:2321-2322
[48] W. Z. Wang, Y. Geng, Y. T. Qian et al, Synthesis and characterization of nanocrystalline Bi2Se3 by solvothermal method. Mater.Res.Bull. 1999, 34(1):131-134
[49] B. Li, Y. Xie, J. Huang et al, Sonochemical synthesis of silver, copper and lead selenides. Ultrasonics Sonoehemistry, 1999, 6(4):217
[50] W. Z. Wang, Y. Geng, Y. T. Qian et al, A novel room temperature method to nanocrystalline Ag2Se. Mater.Res.Bull. 1999, 34(6):877-882
[51] W. Z. Wang and Y. Geng, A convenient, low temperature route to nanocrystalline SnSe. Mater.Res.Bull. 1999, 34(3):403-406
[52] Y. Xie, H. Su, B. Li et al, A direct solvothermal route to nanocrystalline selenides at low temperature. Mater.Res.Bull. 2000, 35(3):459-464
[53] H. Su, Y. Xie, B. Li et al, A simple, convenient, mild hydrothermal route tonanocrystalline CuSe and Ag2Se. Mater.Res.Bull. 2000, 35(3):465-469
[54] M Ferhat and J Nagao, Thermoelectric and transport properties ofβ-Ag2Se compounds. J. Appl. Phys. 2000, 88(2):813
[55]郭世宜,刘璐,利用室温转化法合成硒化银量子点,南开大学学报,2004, 37(2):107-110
[56]夏传俊,杨耿,室温合成硒化银纳米粒子及其X射线光电子能谱表征,安徽大学学报,2004,28(2):75-78
[57] Junqing Hu, Qingyi Lu, Kaibin Tang et al, Hydrothermal growth ofβ-Ag2Se tubular crystals, Chem. commun. 2000, 5:715-716
[58]金盈,吴有吉,Ag2Se纳米晶的水热合成与表征,安徽工程科技学院学报,2005, 20(3):14-16
[59] S. K. Batabyal, C. Basu , A. R. Das et al, Micropatterns of Ag2Se Nanocrystals, Crystal Growth & Design, 2004, 4(3):509-511
[60] B. Pejova, M. Najdoski, I. Grozdanov et al, Chemical bath deposition of nanocrystalline (111) textured Ag2Se thin films. Materials Letters, 2000, 43(5):269-273
[61] S. S. Manoharan, S. J. Prasanna, D. E. Kiwitz et al, Magnetoresistance in microwave synthesized Ag2+δSe (0.0≤δ≤0.2). Phys. Rev. B, 2001, 63(21):212405
[62] Hu Jingshi and T. F. Rosenbaum, Current Jets, Disorder, and Linear Magnetoresistance in the Silver Chalcogenides. Phys. Rev. L, 2005, 95:186603
[63]杨凤霞,邓宗伟,张端明等,硒化银纳米颗粒和晶体的制备及其表征,纳米科技,2008, 5(2):47-49
[64] Li Bin, Xie Yi, Liu Yu et al, Sonochemical synthesis of nanocrystalline silver tellurides Ag2Te and Ag7Te4. J Solid State Chem, 2001, 158:260-263
[65] J Bardeen, F J Blatt and L H Hall, Indirect Transitions from the Valence to the Conduction Bands. Proc. Photoconductivity Conf.(New York: Wiley), 1956,p146
[66] M C Santhosh Kumar and B Pradeep, Structural, electrical and optical properties ofsilver selenide thin films. Semicond. Sci. Technol. 2002,17(3):261-265
[67]刘恩科等,半导体物理学(第6版),科学出版社,2003年
[2] R. P. Hunt, Magnetoresistive Read Out Transducer. IEEE Trans, Magn, 1971, 7:150
[3] M. N. Baibich, J. M. Broto, A. Fert et al, Giant Magnetoresistance of (001)Fe/(001)Cr Magnetic Super- latices. Phys.Rev.Let. 1988, 61(21):2472-2475
[4] B. Dieny, V. S. Speriosu, S. P. Parkin et al, Giant Magnetoresistance in Soft Ferromagnetic Multilayers. Phys.Rev. B, 1991, 43(1):1297
[5] S. Jin, T. H. Tiefel, M. McCormack et al, Thousandfold Change in Resistivity in Magnetoresistive La-Ca-Mn-O Films. Science, 1994, 264:413
[6] T. Miyazaki and N. Tezuka, Giant Magnetic Tunneling Effect in Fe/A1203/Fe Junction. Magn. Mater, 1995, 139:L231-L234
[7] P. A. Penz and R. Bowers, Strain-Dependent Magnetoresistance of Potassium. Phys. Rev. 1968, 172:991
[8] B K Jones, Strain-Dependent Magnetoresistance of Sodium and Potassium. Phys. Rev.1969,179:637
[9] J. S. Lass, Induced torque in an ellipsoid. Torque anisotropy in potassium. J. Phys. C: Solid State Phys. 1970, 3:1926
[10] H. Taub, R. L. Schmidt, B. Maxwell et al, Study of the Transverse Magnetoresistance of Polycrystalline Potassium. Phys. Rev. B, 1971, 4:1134
[11] A. M. Simpson, Magnetoresistance of potassium. J. Phys. F: Met. Phys. 1973, 3:1471
[12] R S Newrock, B W Maxwell, Transverse thermal magnetoresistance of potassium. J. Low Temp. Phys. 1976, 23:119
[13] F R Fickett, Magnetoresistance of Very Pure Polycrystalline Aluminum. Phys. Rev. B, 1971, 3:1941
[14] J C Garland and R Bowers, High-Field Galvanomagnetic Properties of Indium. Phys.Rev. 1969, 188:1121
[15] J E Huffman, M L Snodgrass and F J Biatt, Magnetoresistance of copper, gold, and indium. Phys. Rev. B, 1981, 23:483
[16] W. Schneider, H. Bruhms and K. Hubner, Geometric manipulation of the high-field linear magnetoresistance. J. Phys. Chem. Solids, 1980, 41:313
[17] R. S. Allgaier, J. B. Restorff and Bland Houston, Weak- and strong-field magnetoresistance in (111)-oriented n-type PbTe epitaxial films between 1.8 and 300 K. J. Appl. Phys. 1982, 53(4):3110
[18] J. W. Gallagher and W. F. Love, Transverse Magnetoresistance in n-Type Germanium. Phys. Rev. 1967, 161:793
[19] H. Weiss, Structure and Applications of Galvanomagnetic Devices, New York: Pergamon Press, 1969
[20] R. Xu, A. Husmann, T. F. Rosenbaum et al, Large Magnetoresistance in non-magnetic silver chalcogenides. Nature, 1997, 390(6):57-60
[21] M Kobayashi, Review on structural and dynamical properties of silver chalcogenides. Solid State Ionics, 1990, 39(3-4):212-149
[22] A. J. Frueh, The crystallography of silver sulfide, Ag2S. Jr. Z. Krist. 1959, 112:44
[23] P. Junod and A. Helv, Electrical properties of Ag2Se. Phys. Acta. 1957, 30:470
[24] K. M. Kulinowski, Peng Jiang, H. Vaswani et al, Porous Metals from Colloidal Templates. 2000,12(11): 833-838
[25]萨拉蒙( M. B. Salamon) ,快离子导体物理,北京:科学出版社,1984,16-17
[26] F. Shimojo and H. Okazaki, Boundary Condition Effect in MD Simulation: A Case of theα→βPhase Transition in Superonic Conductor Ag2Se. J. Phys. Soc. Jpn, 1993, 62(1):179-182
[27] K. L. Lewis, X. Zhang, X. F. Qian et al, Ultrafine Powder of Silver Suulfide Semiconductor Prepared in Alcohol Soloution. Mater. Res. Bull. 1998,33(7):1083-1086
[28] K. L. Lewis, A. M. Pitt, P. Wyatt-Davies et al, Crystal gazing into the future of optical coatings. Mater. Res. Soc. Symp. Proc. 1994, 374:105
[29] H. S. Schnyders, M. L. Saboungi, T. F. Rosenbaum, Magnetoresistance in n- and p-type Ag2Te: Mechanisms and applications. Appl. Phys. Lett.2000, 76:13
[30] A. Husmann, J. B. Betts, G. S. Boebinger et al, Megagauss sensors. Nature, 2002, 417 (23):421-424
[31] G Beck, J Janek, Positive and negative magnetoresistance in the system silver–selenium. Physica B, 2001, 086:308-310
[32] G Beck, C Korte, J Janek et al, The magnetoresistance of homogeneous and heterogeneous silver-rich silver selenide. J. Appl. Phys. 2004, 96:5619
[33] J. Janek, B. Mogwitz, G. Beck et al, The magnetoresistance of metal-rich Ag2+xSe-A prototype nanoscale metal/semiconductor dispersion?. Progress in Solid State Chemistry, 2004,32:179-205
[34] G. Beck and J. Janek, Negative and linear positive magnetoresistance effect in silver-rich silver selenide. Solid State Sciences, 2008, 10:776-789
[35] M. von Kreutzbruck, B. Mogwitz,F. Gruhl et al, Magnetroresistance in Ag2+δSe with high silver excess. Appl. Phys. Lett., 2005,86:072102
[36] B Mogwitz, C Korte, J Janek et al, Preparation and magnetoresistance of Ag2+xSe thin films deposited via pulsed laser deposition. J. Appl. Phys., 2007,101:043510
[37] C. N. Rao and A. K. Cheetham, Science and technology of nanomaterials: current status and future prospects. J. Mater. Chem. 2001, 11:2887-2894
[38] H. Toyoji and Y. Hiroshi, Jpn. Kokai Tokyo Kaho JP 02, 1990, 173:622
[39] G. Henshaw, I. P. Parkin, G. Shaw et al, Convenient, Low-energy Synthesis of Metalsulfides and Selenides; PBE, AG2E, ZNE, CDE (E = S, SE). Chem.Comm. 1996, 10:1095-1096
[40] G. Henshaw, I. P. Parkin, G. Shaw et al, Convenient, room-temperature liquidammonia routes to metal chalcogenides. J.Chem.Soc.DaltonTrans. 1997, 2:231-236
[41] V. Dusastre, B. Omar, I. P. Parkin et al, Convenient, room-temperature, amine-assisted routes to metal sulfides, selenides and tellurides. J.Chem.Soc.DaltonTrans. 1997, 19:3505-3508
[42] G. Henshaw, I. P. Parkin and G. Shaw et al, Elemental, liquid ammonia facilitated routed to zinc, cadmium, mercury copper, silver and lead telluride. J. Mater. Sci. Lett. 1996, 15(20):1741-1742
[43] O. Akira, Jpn. Kokai Tokyo Kaho JP61, 1986, 222:910
[44] T. Ohtani, M. Motoki, K. Koh et al, Synthesis of binary copper chalcogenides by mechanical alloying. Mater.Res.Bull. 30(12):1495-1504
[45] T. Ohtani, K. Maruyama and K. Ohshima, Synthesis of copper, silver, and samarium chalcogenides by mechanical alloying. Mater.Res.Bull. 1997, 32(3):343-350
[46] W. Z. Wang, Y. Geng, P. Yan et al, A Novel Mild Route to Nanocrystalline Selenides at Room Temperature. J.Am.Cho.Soc. 1999, 121(16):4062-4063
[47] W. Z. Wang, P. Yan, F. Y. Liu et al, Preparation and characterization of nanocrystalline Cu2–xSe by a novel solvothermal pathway. J. Mater.Chem. 1998, 11:2321-2322
[48] W. Z. Wang, Y. Geng, Y. T. Qian et al, Synthesis and characterization of nanocrystalline Bi2Se3 by solvothermal method. Mater.Res.Bull. 1999, 34(1):131-134
[49] B. Li, Y. Xie, J. Huang et al, Sonochemical synthesis of silver, copper and lead selenides. Ultrasonics Sonoehemistry, 1999, 6(4):217
[50] W. Z. Wang, Y. Geng, Y. T. Qian et al, A novel room temperature method to nanocrystalline Ag2Se. Mater.Res.Bull. 1999, 34(6):877-882
[51] W. Z. Wang and Y. Geng, A convenient, low temperature route to nanocrystalline SnSe. Mater.Res.Bull. 1999, 34(3):403-406
[52] Y. Xie, H. Su, B. Li et al, A direct solvothermal route to nanocrystalline selenides at low temperature. Mater.Res.Bull. 2000, 35(3):459-464
[53] H. Su, Y. Xie, B. Li et al, A simple, convenient, mild hydrothermal route tonanocrystalline CuSe and Ag2Se. Mater.Res.Bull. 2000, 35(3):465-469
[54] M Ferhat and J Nagao, Thermoelectric and transport properties ofβ-Ag2Se compounds. J. Appl. Phys. 2000, 88(2):813
[55]郭世宜,刘璐,利用室温转化法合成硒化银量子点,南开大学学报,2004, 37(2):107-110
[56]夏传俊,杨耿,室温合成硒化银纳米粒子及其X射线光电子能谱表征,安徽大学学报,2004,28(2):75-78
[57] Junqing Hu, Qingyi Lu, Kaibin Tang et al, Hydrothermal growth ofβ-Ag2Se tubular crystals, Chem. commun. 2000, 5:715-716
[58]金盈,吴有吉,Ag2Se纳米晶的水热合成与表征,安徽工程科技学院学报,2005, 20(3):14-16
[59] S. K. Batabyal, C. Basu , A. R. Das et al, Micropatterns of Ag2Se Nanocrystals, Crystal Growth & Design, 2004, 4(3):509-511
[60] B. Pejova, M. Najdoski, I. Grozdanov et al, Chemical bath deposition of nanocrystalline (111) textured Ag2Se thin films. Materials Letters, 2000, 43(5):269-273
[61] S. S. Manoharan, S. J. Prasanna, D. E. Kiwitz et al, Magnetoresistance in microwave synthesized Ag2+δSe (0.0≤δ≤0.2). Phys. Rev. B, 2001, 63(21):212405
[62] Hu Jingshi and T. F. Rosenbaum, Current Jets, Disorder, and Linear Magnetoresistance in the Silver Chalcogenides. Phys. Rev. L, 2005, 95:186603
[63]杨凤霞,邓宗伟,张端明等,硒化银纳米颗粒和晶体的制备及其表征,纳米科技,2008, 5(2):47-49
[64] Li Bin, Xie Yi, Liu Yu et al, Sonochemical synthesis of nanocrystalline silver tellurides Ag2Te and Ag7Te4. J Solid State Chem, 2001, 158:260-263
[65] J Bardeen, F J Blatt and L H Hall, Indirect Transitions from the Valence to the Conduction Bands. Proc. Photoconductivity Conf.(New York: Wiley), 1956,p146
[66] M C Santhosh Kumar and B Pradeep, Structural, electrical and optical properties ofsilver selenide thin films. Semicond. Sci. Technol. 2002,17(3):261-265
[67]刘恩科等,半导体物理学(第6版),科学出版社,2003年