Remarkable room-temperature ferromagnetism was observed both in undoped and Cu-doped rutile TiO2 single crystals（SCs）.To tune their magnetism,Ar ion irradiation was quantitatively performed on the two crystals in wh...Remarkable room-temperature ferromagnetism was observed both in undoped and Cu-doped rutile TiO2 single crystals（SCs）.To tune their magnetism,Ar ion irradiation was quantitatively performed on the two crystals in which the saturation magnetizations for the samples were enhanced distinctively.The post-irradiation led to a spongelike layer in the near surface of the Cu-doped TiO2.Meanwhile,a new CuO-like species present in the sample was found to be dissolved after the post-irradiation.Analyzing the magnetization data unambiguously reveals that the experimentally observed ferromagnetism is related to the intrinsic defects rather than the exotic Cu ions,while these ions are directly involved in boosting the absorption in the visible region.展开更多
Long-term room-temperature annealing effects of InGaAs/InP quantum wells with different wells （namely triple wells and five wells embedded） and bulk InCaAs are investigated after high energy electron irradiation. It...Long-term room-temperature annealing effects of InGaAs/InP quantum wells with different wells （namely triple wells and five wells embedded） and bulk InCaAs are investigated after high energy electron irradiation. It is observed that the photoluminescence （PL） intensity of bulk InGaAs materials is enhanced after low dose electron irradiation and the PL intensity for all the three samples is degraded dramatically when the electron dose is relatively high. With respect to the room-temperature annealing, we find that the PL intensity for both samples recovers relatively fast at the initial stage. The PL performance of multiple quantum-well samples shows better recovery after irradiation compared with the results of bulk InGaAs materials. Meanwhile, the recovery speed factors of multiple quantum-well samples are relatively faster than those of the bulk InGaAs materials as well. We infer that the recovery difference between the quantum-well materials and bulk materials originates from the fact that the radiation induced defects are confined in the quantum wells as a consequence of the free energy barrier between the In0.53Ga0.47 As wells and InP barrier layers.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.11575074)the Open Project of State Key laboratory of Crystal Material,Shandong University,China(Grant No.KF1311)+2 种基金the Open Project of Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education,Lanzhou University,China(Grant No.LZUMMM2012003)the Open Project of Key Laboratory of Beam Technology and Material Modification of Ministry of Education,Beijing Normal University,China(Grant No.201204)the Fundamental Research Funds for the Central Universities,China(Grant No.lzujbky-2015-240)
文摘Remarkable room-temperature ferromagnetism was observed both in undoped and Cu-doped rutile TiO2 single crystals（SCs）.To tune their magnetism,Ar ion irradiation was quantitatively performed on the two crystals in which the saturation magnetizations for the samples were enhanced distinctively.The post-irradiation led to a spongelike layer in the near surface of the Cu-doped TiO2.Meanwhile,a new CuO-like species present in the sample was found to be dissolved after the post-irradiation.Analyzing the magnetization data unambiguously reveals that the experimentally observed ferromagnetism is related to the intrinsic defects rather than the exotic Cu ions,while these ions are directly involved in boosting the absorption in the visible region.
文摘Long-term room-temperature annealing effects of InGaAs/InP quantum wells with different wells （namely triple wells and five wells embedded） and bulk InCaAs are investigated after high energy electron irradiation. It is observed that the photoluminescence （PL） intensity of bulk InGaAs materials is enhanced after low dose electron irradiation and the PL intensity for all the three samples is degraded dramatically when the electron dose is relatively high. With respect to the room-temperature annealing, we find that the PL intensity for both samples recovers relatively fast at the initial stage. The PL performance of multiple quantum-well samples shows better recovery after irradiation compared with the results of bulk InGaAs materials. Meanwhile, the recovery speed factors of multiple quantum-well samples are relatively faster than those of the bulk InGaAs materials as well. We infer that the recovery difference between the quantum-well materials and bulk materials originates from the fact that the radiation induced defects are confined in the quantum wells as a consequence of the free energy barrier between the In0.53Ga0.47 As wells and InP barrier layers.
