The magnetostriction and acoustics properties of Tb1-x xDyx (Fe1-yMny) 1.95 alloys and their application to sonar transducers were studied. The following results were obtained from experiments. When the applied magn...The magnetostriction and acoustics properties of Tb1-x xDyx (Fe1-yMny) 1.95 alloys and their application to sonar transducers were studied. The following results were obtained from experiments. When the applied magnetic field intensity is ≥ 800 kA·m-1, the magnetostrictive coefficients are (1300- 1800)× 10-6. The electromechanical coupling factors are 0.84-0.93, the sound velocities 2168-2856 m·s-1 and the Young's modulus (5.06- 7.26) ×10 N·m-2. A sonar transducer made of the alloy rod, which has a total length of 300 mm and a total weight of 2 kg, is characterized by 2.4 kHz specified resonant frequency, 1 kHz frequency band, 173 kB current response and 45% electroacoustic efficiency.展开更多
For the in-memory computation architecture,a ferroelectric semiconductor field-effect transistor(FeSFET)incorporates ferroelectric material into the FET channel to realize logic and memory in a single device.The emerg...For the in-memory computation architecture,a ferroelectric semiconductor field-effect transistor(FeSFET)incorporates ferroelectric material into the FET channel to realize logic and memory in a single device.The emerging groupⅢnitride material Al_(1-x)Sc_(x)N provides an excellent platform to explore FeSFET,as this material has significant electric polarization,ferroelectric switching,and high carrier mobility.However,steps need to be taken to reduce the large band gap of~5 eV of Al_(1-x)Sc_(x)N to improve its transport property for in-memory logic applications.By state-of-the-art first principles analysis,here we predict that alloying a relatively small amount(less than~5%)of Sb impurities into Al_(1-x)Sc_(x)N very effectively reduces the band gap while maintaining excellent ferroelectricity.We show that the co-doped Sb and Sc act cooperatively to give a significant band bowing leading to a small band gap of~1.76 eV and a large polarization parameter~0.87 C/m^(2),in the quaternary Al_(1-x)Sc_(x)Sb_(y)N_(1-y)compounds.The Sb impurity states become more continuous as a result of interactions with Sc and can be used for impurity-mediated transport.Based on the Landau-Khalatnikov model,the Landau parameters and the corresponding ferroelectric hysteresis loops are obtained for the quaternary compounds.These findings indicate that Al_(1-x)Sc_(x)Sb_(y)N_(1-y)is an excellent candidate as the channel material of FeSFET.展开更多
基金the Rare Earth Office of MMI and the National Natural Science Foundation of China!59501008
文摘The magnetostriction and acoustics properties of Tb1-x xDyx (Fe1-yMny) 1.95 alloys and their application to sonar transducers were studied. The following results were obtained from experiments. When the applied magnetic field intensity is ≥ 800 kA·m-1, the magnetostrictive coefficients are (1300- 1800)× 10-6. The electromechanical coupling factors are 0.84-0.93, the sound velocities 2168-2856 m·s-1 and the Young's modulus (5.06- 7.26) ×10 N·m-2. A sonar transducer made of the alloy rod, which has a total length of 300 mm and a total weight of 2 kg, is characterized by 2.4 kHz specified resonant frequency, 1 kHz frequency band, 173 kB current response and 45% electroacoustic efficiency.
基金supported by the National Natural Science Foundation of China(Grant No.12347101)(Shujin Guo)financial support by the National Natural Science Foundation of China(Grant No.12104313)(Xianghua Kong)+3 种基金Department of Science and Technology of Guangdong Province(Grant No.2021QN02L820)(Xianghua Kong)Shenzhen Science and Technology Program(Grant No.RCYX20231211090126026)(Xianghua Kong)Shenzhen Natural Science Fund(the Stable Support Plan Program)(Grant No.20220810161616001)(Xianghua Kong)Natural Sciences and Engineering Research Council(NSERC)of Canada(Hong Guo)。
文摘For the in-memory computation architecture,a ferroelectric semiconductor field-effect transistor(FeSFET)incorporates ferroelectric material into the FET channel to realize logic and memory in a single device.The emerging groupⅢnitride material Al_(1-x)Sc_(x)N provides an excellent platform to explore FeSFET,as this material has significant electric polarization,ferroelectric switching,and high carrier mobility.However,steps need to be taken to reduce the large band gap of~5 eV of Al_(1-x)Sc_(x)N to improve its transport property for in-memory logic applications.By state-of-the-art first principles analysis,here we predict that alloying a relatively small amount(less than~5%)of Sb impurities into Al_(1-x)Sc_(x)N very effectively reduces the band gap while maintaining excellent ferroelectricity.We show that the co-doped Sb and Sc act cooperatively to give a significant band bowing leading to a small band gap of~1.76 eV and a large polarization parameter~0.87 C/m^(2),in the quaternary Al_(1-x)Sc_(x)Sb_(y)N_(1-y)compounds.The Sb impurity states become more continuous as a result of interactions with Sc and can be used for impurity-mediated transport.Based on the Landau-Khalatnikov model,the Landau parameters and the corresponding ferroelectric hysteresis loops are obtained for the quaternary compounds.These findings indicate that Al_(1-x)Sc_(x)Sb_(y)N_(1-y)is an excellent candidate as the channel material of FeSFET.
