"A Series of Experimental Studies on Phase Transitions, Photo-Disclosed Ordered States, Dynamics of Superconductive-Conjugate Optical Phenomena in Oxide Systems"

1.浮区法精炼及氧化材料评价采用光谱化学分析、x射线衍射、光吸收、光致发光和拉曼散射等方法研究了高纯度Cu_2O和CuO样品作为铜酸超导氧化物中Cu-O网络的基本物质。这些结果揭示了Cu_2O，特别是CuO.2的新结果。用反常康普顿散射试验研究绝缘氧化物的相变我们试图通过研究Cu_2O中异常康普顿散射中动量分布和自旋极化的温度依赖性（T=15-300K）来追求价电子系统相变的潜在存在。不幸的是，由于在高能物理实验室（KEK）的同步辐射轨道（SOR）设施中缺乏可用的机器时间，没有得到明确的结果。相变与光电导率异常发生的相关性研究在更广阔的视野下，我们通过研究各种物质中脉冲光电导率的温度依赖性，特别是在更宽的电场和磁场、光激发的波长和强度下，详细地研究了温度下降时意想不到的光信号，扩展了相变和光电导率异常发生之间的相关性。特别是，除了Cu_2O外，我们还将研究扩展到CuO，Sm_2CuO_4等，得到了与Cu_2O非常相似的结果。3 .我们正通过光电作用接近铜氧基超导体。非线性光磁-光-微波回旋双共振本文详细研究了Cu_2O由极化子和激子引起的非线性光微波双回旋共振。此外，在Cu_2O中存在中隙态的问题上，我们从35GHz光响应的动力学角度，重新研究了T=4.2K和300K之间微波光电导信号与脉冲光电导信号的温度依赖关系。我们在λ =614nm和T=60K.5附近观察到微波光导率的共振增强。超导共轭光导物质的寻找和光响应动力学研究了CuO、Sm_2CuO_4等单晶、多晶及薄膜的光吸收、光电导率、光致发光性能。并新证实了CuO和Sm_2CuO_4表现出超导共轭光电性。我们还研究了Ba_<1-x>K_xBiO_3的光吸收和光照射对还原Y-Ba_2-Cu_3-O_<7- δ >.6的影响。超导光电器件的基础研究利用Cu-O基高tc超导体对与超导共轭光导绝缘体Cu_2O的结合，探索了超导光电子器件的构建及其应用的可能性。在基本方面，我们发现随着Y-Ba-Cu-O、La-Sr-Cu-O或La-Ba-Cu-O在源极区和漏极区发生超导跃迁，栅极区Cu_2O光导率的温度依赖性发生共振位移。在应用方面，我们确认了光电晶体管的基本操作的可能性，包括三个终端fet的安排。这些结果揭示了在高密度和高速操作下开发光电器件集成阵列的可能性。少

1.Refining by Floating Zone Technique and Evaluation of Oxide Materials ; High-purity specimens of Cu_2O and CuO have been studied as the basic substances towards the Cu-O network in the Cuprate superconductive Oxides by spectrochemical analysis, X-ray diffraction, optical absorption, photoluminescence, and Raman scattering. These results revealed remakably new results both on Cu_2O and especially on CuO.2.A Trial Study of Phase Transition in Insulating Oxides by using the Anomalous Compton Scattering ; We have tried to pursue a potential existence of phase transitions of the valence electronic system in Cu_2O via studying the temperature dependence (T=15-300K) of the momentum distribution and spin polarization in the anomalous Compton scattering. Unfortunately, clear results have not been obtained because of lack of machine time available in the Synchrotron Oribit Radiation (SOR) Facilities in the High Energy Physics Laboratory (KEK).3.Studies of the Correlation between Phase Transiti … More ons and Occurrences of Anomalies in Photoconductivity ; With a wider view than ever, we extended our studies on the correlation between phase transitions and occurrences of anomalies in photoconductivity by studying the temperature dependence of pulsed photoconductivity in various substance, especially unexpectedly emerging photosignals with decreasing temperature in details, at wider electric and magnetic fields, wavelength and intensity of photoexcitation. Particularly, besides Cu_2O,we have extended studies to cover CuO,Sm_2CuO_4, etc.and obtained results remarkably similar to those in Cu_2O.We are approaching the Cu-O based superconductors by photodoping.4.Nonlinear Photomagnetism-Optical-Microwave Cyclotrone Double Resonance ; We have investigated intensively the nonlinear optical-microwave double cyclotron resonance of Cu_2O due to polarons with excitons in details. Besides, on the problem of an existence of the mid-gap states in Cu_2O,we newly studied the temperature dependence of microwave photoconductivity signals between T=4.2K and 300K similar to pulsed photoconductivity signals in a view of dynamical aspects of photoresponses at 35GHz. We have observed a resonant enhancement of microwave photoconductivity at lambda=614nm and around T=60K.5.Search for Superconductive-Conjugate Photoconductive Substance and Dynamics of Photoresponses ; We have examined the optical absorption, photoconductivity, photoluminescence of single or polycrystals and thin film of CuO,Sm_2CuO_4, etc.. and newly confirmed that CuO and Sm_2CuO_4 exhibit superconductive-conjugate photoconductivity. We have also studied the optical absorption of Ba_<1-x>K_xBiO_3 and light-irradiated effect on reduced Y-Ba_2-Cu_3-O_<7-delta>.6.Basic Studies of Superconductive Optoelectronic Devices ; By adopting a combination of the Cu-O based high-Tc Superconductor pairs and the insulator Cu_2O of superconductive-conjugate photoconductivity, we have pursued a possibility to build a superconductive optoelectronic device and of their application. In a basic aspect, we discovered a resonant shift of temperature dependence of photoconductivity of Cu_2O at the gate region with the occurrence of superconductive transitions of the Y-Ba-Cu-O,La-Sr-Cu-O,or La-Ba-Cu-O at the source and drain regions. In an aspect for applications, we confirmed a possibility of basic operation as a photo-transistor including three terminal FET-like arrangements. These results reveal a possibility to develop an integrated array of photoelectric devices at high density and high speed operations. Less