Achievements

**研究論文 Papers**
アモルファス物質 Amorphous Materials
1.	"Metal-insulator transition in amorphous Si1-xCrxfilms", S. Okuma, S. Shiratake, A. Asamitsu, and N. Nishida, Solid. State Commu. 70 (1989) 1091.
酸化物関連 Oxides Related
2.	"Giant Magnetotransport Phenomena in Filling-Controlled Kondo Lattice System: La1-xSrxMnO3", Y. Tokura, A. Urushibara, Y. Moritomo, T. Arima, A. Asamitsu, G. Kido and N. Furukawa: J. Phys. Soc. Jpn. 63, 3931-3935 (1995).
3.	"Giant Magnetotransport and Magnetostructural Phenomena in Hole-Doped Manganese Oxides", Y. Tokura, A. Urushibara, Y. Moritomo, A. Asamitsu, Y. Tomioka, T. Arima and G. Kido: J. Mater. Sci. Eng. B31, 187-191 (1995).
4.	"Magnetic and electronic properties in hole-doped manganese oxides with layered structures: La1-xSr1+xMnO4", Y. Moritomo, Y. Tomioka, A. Asamitsu, Y. Tokura and Y. Matsui: Phys. Rev. B51, 3297-3231 (1995).
5.	"A structural phase transition induced by an external magnetic field", A. Asamitsu, Y.Moritomo, Y. Tomioka, T. Arima and Y. Tokura: Nature 373, 407-409 (1995).
6.	"Insulator-metal transition and giant magnetoresistance in La1-xSrxMnO3", A. Urushibara, Y. Moritomo, T. Arima, A. Asamitsu, G. Kido and Y. Tokura: Phys. Rev. B51, 14103-14109 (1995).
7.	"Pressure effect on the double exchange ferromagnet La1-xSrxMnO3 (0.15<x<0.5)
8.	"Anomalous Magnetotransport Properties of Pr1-xCaxMnO3", Y. Tomioka, A. Asamitsu, Y. Moritomo and Y. Tokura: J. Phys. Soc. Jpn. 64, 3626-3630 (1995).
9.	"Collapse of a Charge Ordered State under a Magnetic Field in Pr1/2Sr1/2MnO3", Y. Tomioka, A. Asamitsu, Y. Moritomo, H. Kuwahara and Y. Tokura: Phys. Rev. Lett. 74, 5108-5111 (1995).
10.	"A First-Order Phase Transition Induced by a Magnetic Field", H. Kuwahara, Y. Tomioka, A. Asamitsu. Y. Moritomo and Y. Tokura: Science 270, 961-963 (1995).
11.	"Giant Magnetoresistance in Mn-based Layered Perovskite", Y. Moritomo, A. Asamitsu, H. Kuwahara and Y. Tokura: Nature 380, 141-144 (1996).
12.	"Striction-Coupled Magnetoresistance in Perovskite-type Manganese Oxides", H. Kuwahara, Y. Tomioka, A. Asamitsu, M. Kasai, R. Kumai and Y. Tokura: Science 272, 80-82 (1996).
13.	"Thermoelectric effect in double-exchange ferromagnets; La1-xSrxMnO3", A. Asamitsu, Y. Moritomo and Y. Tokura: Phys. Rev. B53, 2952 (1996).
14.	"Competing Instabilities and Robust Metastable States in (Nd,Sm)1/2Sr1/2MnO3", Y. Tokura, H. Kuwahara, Y. Moritomo, Y. Tomioka and A. Asamitsu: Phys. Rev. Lett. 76, 3184-3187 (1996).
15.	"Origins of colossal magnetoresistance in perovskite-type manganese oxides", Y. Tokura, Y. Tomioka, H. Kuwahara, A. Asamitsu, Y. Moritomo and M. Kasai: J. Appl. Phys. 79, 5288-5291 (1996).
16.	"Magnetic field-induced metal-insulator phenomena in Pr1-xCaxMnO3 with controlled charge-ordering instability", Y. Tomioka, A. Asamitsu, H. Kuwahara, Y. Moritomo and Y. Tokura, Phys. Rev. B53, R1689-1692 (1996).
17.	"Magnetostructural phase transitions in La1-xSrxMnO3 with controlled carrier density", A. Asamitsu, Y. Moritomo, R. Kumai, Y. Tomioka and Y. Tokura: Phys. Rev. B54, 1716-1723 (1996).
18.	"Magnetic-field-induced insulator-metal phenomena in perovskite manganese oxides", Y. Tokura, Y. Tomioka, H. Kuwahara, A. Asamitsu, Y. Moritomo and M. Kasai: Physica C263, 544-549 (1996).
19.	"Interplane Tunneling Magnetoresistance in a Layered Manganite Crystal", T. Kimura, Y. Tomioka, H. Kuwahara, A. Asamitsu, M. Tamura and Y. Tokura: Science 274, 1698 (1996).
20.	"Low-Field Colossal Magnetoresistance in Bandwidth-Controlled Manganites", H. Kuwahara, Y. Moritomo, Y. Tomioka, A. Asamitsu, M. Kasai and Y. Tokura: J. Appl. Phys. 81, 4954-4956 (1997).
21.	"Reentrant Transition of the Charge-Ordered State in Perovskite Manganites", Y. Tomioka, A. Asamitsu, H. Kuwahara and Y. Tokura: J. Phys. Soc. Jpn. 66, 302-305 (1997).
22.	"Current-switching of resistive states in colossal magnetoresistive oxides", A. Asamitsu, Y. Tomioka, H. Kuwahara and Y. Tokura: Nature 388, 50 (1997).
23.	"Critical Change of Magnetoresistance with Bandwidth and Bandfilling in Perovskite Manganites", Y. Tomioka, H. Kuwahara, A. Asamitsu, M. Kasai and Y.Tokura: Appl. Phys. Lett. 70, 3609 (1997).
24.	"Spin-Charge-Lattice Coupled Phase Transitions in Bandwidth-Controlled Systems: (Nd,Sm)1/2Sr1/2MnO3", H. Kuwahara, Y. Moritomo, Y. Tomioka, A. Asamitsu, M. Kasai, R. Kumai and Y. Tokura: Phys. Rev. B56, 9386 (1997).
25.	"Magnetic-field-induced metal-insulator transition in perovskite-type manganese oxides", Y. Tomioka, A. Asamitsu, H. Kuwahara, Y. Moritomo, M. Kasai, R. Kumai, and Y. Tokura: Physica B237-238, 6-10 (1997).
26.	Pressure-induced polaronic to itinerant electronic transition in La1-xSrxMnO3 crystals J.-S. Zhou, J. B. Goodenough, A. Asamitsu, and Y. Tokura, Phys. Rev. Lett., 79, 3234 (1997).
27.	"Hall effect in La1-xSrxMnO3", A. Asamitsu and Y. Tokura, Phys. Rev. B58, 47-50 (1998).
28.	"Magnetotransport properties in layered manganite crystals", T. Kimura, Y. Tomioka, H. Kuwahara, A. Asamitsu, and Y. Tokura, Physica C, in press.
29.	"Critical behavior of metal-insulator transition in La1-xSrxMnO3", T. Okuda, A. Asamitsu, Y. Tomioka, T. Kimura, T. Taguchi, and Y. Tokura, Phys. Rev. Lett. 81, 3203-3206 (1998).
30.	"Enhanced electron-lattice coupling in La1-xSrxMnO3 near the metal-insulator phase boundary", Y. Moritomo, A. Asamitsu, and Y. Tokura, Phys. Rev. B56, 12190- 12195 (1997).
31.	"Pressure-enhanced interplane tunneling magnetoresistance in a layered manganite crystal", T. Kimura, A. Asamitsu, Y. Tomioka, and Y. Tokura, Phys. Rev. Lett. 79, 3720-3723 (1997).
有機分子システム関連 Organic Molecular Systems Related
32.	"A Molecular Antiferromagnet TMTSF･FeCl4", R. Kumai, A. Asamitsu and Y. Tokura: Chem. Lett. 1996, 753-754 (1996).
33.	"Magnetic and Transport Properties of Organic Radical Ion Salts Containing Tetrahalogenoferrate Anion", R. Kumai, A. Asamitsu, and Y. Tokura: Synthetic Metals 85, 1681-1682 (1997).
34.	"Band-Filling Control of p-d Electron System Based on BEDT-TTF [bis(ethylenedithio)tetrathiafulvalene] Cation Radical Salts", R. Kumai, A. Asamitsu, and Y. Tokura, J. Am. Chem. Soc. 120, 8263-8264 (1998).
磁性半導体 Magnetic Semiconductors
35.	W. Van Roy, H. Akinaga, S. Miyanishi, and A. Asamitsu, "Correlation between the signs of the magnetoresistance and of the interlayer coupling in MnGa / (Mn,Ga,As) / MnGa trilayers," Appl. Phys. Lett. 71, 971-973 (1997).
36.	"Negative magnetoresistance in GaAs with magnetic MnAs nano-clusters", H. Akinaga, J. De Boeck, G. Borghs, S. Miyanishi, A. Asamitsu, W. Van Roy, Y. Tomioka, and L. H. Kuo, Appl. Phys. Lett. (submitted).

1.	"Onset of superconductivity in the ultra-thin amorphous Nb films", N. Nishida, A. Asamitsu, and S. Okuma, Physica B169 (1991) 487.
2.	"Disappearance of superconductivity in ultra-thin amorphous Nb films", A. Asamitsu, M. Iguchi, A. Ichikawa, and N. Nishida, Physica B194 (1994) 1649.
3.	"Manganese-based magnetic compounds grown on III-V semiconductors: Growth technique, Magnetic properties, and Applications", H. Akinaga, S. Miyanishi, A. Asamitsu, W. Van Roy, L. H. Kuo, Y. Tomioka, J. De Boeck, and G. Borghs, Conference Proceedings of ASDAM '98 (Second International Conference on Advanced Semiconductor Devices and Microsystems), Smolenice Castle, Slovakia, 5-7 October 1998.

1.	"ペロブスカイト型Mn酸化物La1-xSrxMnO3の磁場誘起構造相転移", 朝光　敦、守友　浩、十倉　好紀: 固体物理Vol. 30(8), 733-738 (1995).
2.	"二重交換系の基本物性", 朝光　敦、沖本洋一、十倉好紀: 固体物理Vol. 32(4), 258-271 (1997).
3.	"超巨大磁気抵抗酸化物の物性と相制御", 朝光　敦、十倉好紀: 日本金属学会誌「まてりあ」, in press.
4.	"コロサル磁気抵抗効果"、朝光　敦、十倉　好紀: 電子情報通信学会誌 (to be published).

1.	"Magnetostructural phase transition in La1-xSrxMnO3 with controlled carrier density", A. Asamitsu and Y. Tokura, XVII Congress and General Assembly of the International Union of Crystallography, Seattle, August 1996.
2.	"Charge dynamics in manganites with electronic and magnetic anisotropy ", A. Asamitsu and Y. Tokura, Los Alamos Workshop on Spin-Charge-Lattice Coupling in Complex Electronic Materials, Los Alamos, August 1997.
3.	"Melting of charge-ordered state induced by electric fields and light irradiation ", A. Asamitsu, 1998 March Meeting of the American Physical Society, Los Angeles, 1998.
4.	"Anomalous metallic state and critical behavior of the metal-insulator transition in La1-xSrxMnO3", Telluride Summer School, Illinois, 1998.

1.	「無粒界型マンガン酸化物系結晶体及びスイッチング型磁気抵抗素子」、十倉好紀、朝光　敦、守友　浩、富岡泰秀、1994年10月。
2.	「無粒界型マンガン酸化物系結晶体、その製造方法及びメモリースイッチング型磁気抵抗素子」、朝光　敦、守友　浩、十倉好紀、1994年10月。
3.	「層構造マンガン酸化物系単結晶体及びその製造方法」、守友　浩、朝光　敦、富岡泰秀、十倉好紀、1995年3月。
4.	「無粒界型マンガン酸化物系結晶体及び低磁場感応性磁気抵抗素子」、桑原英樹、十倉好紀、富岡泰秀、朝光　敦、守友　浩、1996年3月。
5.	「マンガン酸化物材料における電流及び電場誘起相転移を利用したスイッチング素子及びメモリー素子」、朝光　敦、富岡泰秀、倉原英樹、十倉好紀、1997年3月。
6.	「光メモリー材料」、桑原英樹、十倉好紀、富岡泰秀、朝光　敦、守友　浩、1997年9月。

業績リスト(Achievements)