Liquid-phase exfoliation was employed to synthesize Sr_(2)Nb_(3)O_(10) perovskite nanosheets with thicknesses down to 1.76 nm.Transmission electron microscopy(TEM),atomic force microscope(AFM),X-ray photoelectron spec...Liquid-phase exfoliation was employed to synthesize Sr_(2)Nb_(3)O_(10) perovskite nanosheets with thicknesses down to 1.76 nm.Transmission electron microscopy(TEM),atomic force microscope(AFM),X-ray photoelectron spectrometer(XPS),and other characterization techniques were used to evaluate the atomic structure and chemical composition of the exfoliated nanosheets.A UV photodetector based on individual Sr_(2)Nb_(3)O_(10) nanosheets was prepared to demonstrate the application of an ultraviolet(UV) photodetector.The UV photodetector exhibited outstanding photocurrent and responsivity with a responsivity of 3×10^(5) A·W^(-1) at 5 V bias under 280 nm illumination,a photocurrent of 60 nA,and an on/off ratio of 3×10^(2).展开更多
Magnetoelectric equivalent circuit analytical method is presented for laminate composites of magneto- strictive Terfenol-D (TbxDy1-xFe2) and piezoelectric Pb(Zr1-xTix)O3 (PZT) operated in longitudinal mag- netized and...Magnetoelectric equivalent circuit analytical method is presented for laminate composites of magneto- strictive Terfenol-D (TbxDy1-xFe2) and piezoelectric Pb(Zr1-xTix)O3 (PZT) operated in longitudinal mag- netized and transverse polarized (or L-T), and transverse magnetized and transverse polarized (or T-T) modes. Magnetoelectric (ME) couplings both at low-frequency and resonance-frequency have been studied, and our analysis predicts that (i) the ME voltage coefficients of both L-T and T-T modes in- crease with increasing the thickness of the piezoelectric phase whereas magnetostrictive phase thickness keeps constant, and then tend to saturation when the thickness ratio of piezoelectric phase to magnetic phases is >3; (ii) there are the optimum thickness ratios that maximize magnetoelectric (ME) voltage coefficients for the two modes, which are dependent on elastic compliances ratio of piezoelec- tric phase and magnetostrictive phase; and (iii) the ME voltage coefficients are dramatically increased by a factor of ~Qm, when operated at resonance frequency. A series of Terfenol-D/PZT laminates were fabricated, and the results were compared with the theoretical ones. Experiments confirmed that equivalent circuit method is a useful tool for optimum designs of ME laminates.展开更多
基金Funded by the National Natural Science Foundation of China(Nos.51872214 and 52172124)the Fundamental Research Funds for the Central Universities(WUT:2021Ⅲ019JC and 2018Ⅲ041GX)。
文摘Liquid-phase exfoliation was employed to synthesize Sr_(2)Nb_(3)O_(10) perovskite nanosheets with thicknesses down to 1.76 nm.Transmission electron microscopy(TEM),atomic force microscope(AFM),X-ray photoelectron spectrometer(XPS),and other characterization techniques were used to evaluate the atomic structure and chemical composition of the exfoliated nanosheets.A UV photodetector based on individual Sr_(2)Nb_(3)O_(10) nanosheets was prepared to demonstrate the application of an ultraviolet(UV) photodetector.The UV photodetector exhibited outstanding photocurrent and responsivity with a responsivity of 3×10^(5) A·W^(-1) at 5 V bias under 280 nm illumination,a photocurrent of 60 nA,and an on/off ratio of 3×10^(2).
基金Supported by the Office of Naval Research in USA
文摘Magnetoelectric equivalent circuit analytical method is presented for laminate composites of magneto- strictive Terfenol-D (TbxDy1-xFe2) and piezoelectric Pb(Zr1-xTix)O3 (PZT) operated in longitudinal mag- netized and transverse polarized (or L-T), and transverse magnetized and transverse polarized (or T-T) modes. Magnetoelectric (ME) couplings both at low-frequency and resonance-frequency have been studied, and our analysis predicts that (i) the ME voltage coefficients of both L-T and T-T modes in- crease with increasing the thickness of the piezoelectric phase whereas magnetostrictive phase thickness keeps constant, and then tend to saturation when the thickness ratio of piezoelectric phase to magnetic phases is >3; (ii) there are the optimum thickness ratios that maximize magnetoelectric (ME) voltage coefficients for the two modes, which are dependent on elastic compliances ratio of piezoelec- tric phase and magnetostrictive phase; and (iii) the ME voltage coefficients are dramatically increased by a factor of ~Qm, when operated at resonance frequency. A series of Terfenol-D/PZT laminates were fabricated, and the results were compared with the theoretical ones. Experiments confirmed that equivalent circuit method is a useful tool for optimum designs of ME laminates.
