ZnO thin film growth prefers different orientations on the etched and unetched SrTiO 3（STO）（110） substrates.Inclined ZnO and cobalt-doped ZnO（ZnCoO） thin films are grown on unetched STO（110） substrates using o...ZnO thin film growth prefers different orientations on the etched and unetched SrTiO 3（STO）（110） substrates.Inclined ZnO and cobalt-doped ZnO（ZnCoO） thin films are grown on unetched STO（110） substrates using oxygen plasma assisted molecular beam epitaxy,with the c-axis 42 inclined from the normal STO（110） surface.The growth geometries are ZnCoO[100]//STO[110] and ZnCoO[111]//STO[001].The low temperature photoluminescence spectra of the inclined ZnO and ZnCoO films are dominated by D 0 X emissions associated with A 0 X emissions,and the characteristic emissions for the 2 E（2G）→ 4A2（4F） transition of Co 2＋ dopants and the relevant phonon-participated emissions are observed in the ZnCoO film,indicating the incorporation of Co 2＋ ions at the lattice positions of the Zn 2＋ ions.The c-axis inclined ZnCoO film shows ferromagnetic properties at room temperature.展开更多
EuS is one of typical ferromagnetic semiconductor using as spin filter in spintronic devices,and the doped one could be a good spin injector.Herein,we fabricate a spin-functional tunnel junction by epitaxially growing...EuS is one of typical ferromagnetic semiconductor using as spin filter in spintronic devices,and the doped one could be a good spin injector.Herein,we fabricate a spin-functional tunnel junction by epitaxially growing the ferromagnetic EuS film on Nb-doped SrTiO3.The improvement of Curie temperature up to 35 K is associated with indirect exchange through additional charge carriers at the interface of EuS/Nb:STO junction.Its magnetic field controlled current-voltage curves indicate the large magnetoresistance(MR)effect in EuS barriers as a highly spin-polarized injector.The negative MR is up to 60%in 10-nm EuS/Nb:STO at 4 T and 30 K.The MR is enhanced with increasing thickness of EuS barrier.The large negative MR effect over a wide temperature range makes this junction into a potential candidate for spintronic devices.展开更多
We have performed time-resolved degenerate four-wave mixing (DFWM) experiments in 75Nb2O5-20TeO2-5ZnO glasses doped by Er2O3 at different excitation intensities and lattice temperatures. DFWM signal exhibits three pea...We have performed time-resolved degenerate four-wave mixing (DFWM) experiments in 75Nb2O5-20TeO2-5ZnO glasses doped by Er2O3 at different excitation intensities and lattice temperatures. DFWM signal exhibits three peaks at high excitation intensities, where a main peak appears at zero time delay and two rather weak side peaks locate symmetrically at the negative and positive time delay, respectively. The main peak is attributed to local-field effect and two side peaks are attributed to Coulomb interaction (CI).展开更多
基金Project supported by the National Basic Research Program of China (Grant No. 2009CB929202)the National Natural ScienceFoundation of China (Grant Nos. 10834001 and 51125004)
文摘ZnO thin film growth prefers different orientations on the etched and unetched SrTiO 3（STO）（110） substrates.Inclined ZnO and cobalt-doped ZnO（ZnCoO） thin films are grown on unetched STO（110） substrates using oxygen plasma assisted molecular beam epitaxy,with the c-axis 42 inclined from the normal STO（110） surface.The growth geometries are ZnCoO[100]//STO[110] and ZnCoO[111]//STO[001].The low temperature photoluminescence spectra of the inclined ZnO and ZnCoO films are dominated by D 0 X emissions associated with A 0 X emissions,and the characteristic emissions for the 2 E（2G）→ 4A2（4F） transition of Co 2＋ dopants and the relevant phonon-participated emissions are observed in the ZnCoO film,indicating the incorporation of Co 2＋ ions at the lattice positions of the Zn 2＋ ions.The c-axis inclined ZnCoO film shows ferromagnetic properties at room temperature.
基金Project supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant Nos.XDB28000000 and XDB07000000)the National Key Research and Development Program of China(Grant No.2016YFA0300600)the Fund from the Beijing Municipal Science&Technology Commission(Grant No.Z191100007219012).
文摘EuS is one of typical ferromagnetic semiconductor using as spin filter in spintronic devices,and the doped one could be a good spin injector.Herein,we fabricate a spin-functional tunnel junction by epitaxially growing the ferromagnetic EuS film on Nb-doped SrTiO3.The improvement of Curie temperature up to 35 K is associated with indirect exchange through additional charge carriers at the interface of EuS/Nb:STO junction.Its magnetic field controlled current-voltage curves indicate the large magnetoresistance(MR)effect in EuS barriers as a highly spin-polarized injector.The negative MR is up to 60%in 10-nm EuS/Nb:STO at 4 T and 30 K.The MR is enhanced with increasing thickness of EuS barrier.The large negative MR effect over a wide temperature range makes this junction into a potential candidate for spintronic devices.
基金This work was suPPorted by Shanghai Priority Academic DisciPline,the National Natural Science Foundation of China(No.10234030 and 10074015),the National Key Project for Basic Research(No.1999075204),the Project Sponsored by Shangliai Science and Tech
文摘We have performed time-resolved degenerate four-wave mixing (DFWM) experiments in 75Nb2O5-20TeO2-5ZnO glasses doped by Er2O3 at different excitation intensities and lattice temperatures. DFWM signal exhibits three peaks at high excitation intensities, where a main peak appears at zero time delay and two rather weak side peaks locate symmetrically at the negative and positive time delay, respectively. The main peak is attributed to local-field effect and two side peaks are attributed to Coulomb interaction (CI).
