We design a Blatter radical-based molecular spintronic device, and investigate its spin-polarized transport properties using density functional theory and non-equilibrium Green's function technique. High-performan...We design a Blatter radical-based molecular spintronic device, and investigate its spin-polarized transport properties using density functional theory and non-equilibrium Green's function technique. High-performance spin-rectifying and spin-filtering effects are realized. The physical mechanism is explained by the spin-resolved bias voltage-dependent transmission spectra, the energy levels of the corresponding molecular projected self-consistent Hamiltonian orbitals, and their spatial distributions. The results demonstrate that the Blatter radical has great potential in the development of highperformance multifunctional molecular spintronic devices.展开更多
A recent theoretical estimation indicated that the NM/FI/FI/NM double spin-filter junction (DSFJ, here the NM and FI represent the nonmagnetic electrode and the ferromagnetic insulator (semiconductor) spacer, respecti...A recent theoretical estimation indicated that the NM/FI/FI/NM double spin-filter junction (DSFJ, here the NM and FI represent the nonmagnetic electrode and the ferromagnetic insulator (semiconductor) spacer, respectively) could have very high tunneling magnetoresistance (TMR) at zero bias. To meet the requirement in research and application of the magnetoresistance devices, we have calculated the dependences of tunneling magnetoresistance of DSFJ on the bias (voltage), the thicknesses of ferromagnetic insulators (semiconductors) and the average barrier height. Our results show that except its very high value, the TMR of DSFJ does not decrease monotonously and rapidly with rising bias, but increase slowly at first and decrease then after having reached a maximum value. This feature is in distinct contrast to the ordinary magnetic tunnel junction FM/NI/FM (FM and NI denote the ferromagnetic electrode and the nonmagnetic insulator (semiconductor) spacer, respectively), and is of benefit to the use of DSFJ as a magnetoresistance device.展开更多
We theoretically investigate the spin filtering transport of double parallel quantum wires(QWs) side-coupled to a grapheme sheet and sandwiched between two ferromagnetic(FM) leads.The dependences of the wire-graphene ...We theoretically investigate the spin filtering transport of double parallel quantum wires(QWs) side-coupled to a grapheme sheet and sandwiched between two ferromagnetic(FM) leads.The dependences of the wire-graphene coupling strength,wire-wire coupling strength,as well as the spin polarization of the ferromagnetic leads are studied.It is found that the wire-graphene coupling strength tends to reduce the current and the wire-wire coupling strength can first reinforce and then decrease the current.The spin polarization strength has an enhanced(identical) effect on the current under the parallel(anti-parallel) alignment of the FM leads,which gives rise to an obvious spin-filter and tunnel magnetoresistance(TMR) effect.Our results suggest that such a theoretical model can stimulate some experimental investigations about the spin-filter devices.展开更多
滤料作为袋式除尘器的核心,对其过滤性能具有决定性作用。为了提高过滤性能以满足日益严格的排放要求,基于熔融静电纺丝法自行设计了熔融静电纺丝装置,并进行了滤料纤维的制备。此外,运用扫描电镜(Scanning Electron Microscopy,SEM)、...滤料作为袋式除尘器的核心,对其过滤性能具有决定性作用。为了提高过滤性能以满足日益严格的排放要求,基于熔融静电纺丝法自行设计了熔融静电纺丝装置,并进行了滤料纤维的制备。此外,运用扫描电镜(Scanning Electron Microscopy,SEM)、差示扫描量热(Differential Scanning Calorimeter,DSC)、红外光谱分析(Infrared Radiation,IR)、分粒级过滤效率和阻力测试等多种方法对纤维性能进行了分析。结果表明:自行设计的试验装置可用于熔融静电纺丝;在一定范围内,随着纺丝温度、电场强度和接收距离的提高,纤维直径减小;熔融静电纺丝前后,高分子材料结晶程度和分子结构没有发生明显变化;熔融静电纺丝纤维滤料具有“高效低阻”的特点,验证了其在改善袋式除尘器滤料性能上应用的可行性。展开更多
基金Project supported by the Natural Science Foundation of Shandong Province, China (Grant No. ZR2021MA059)。
文摘We design a Blatter radical-based molecular spintronic device, and investigate its spin-polarized transport properties using density functional theory and non-equilibrium Green's function technique. High-performance spin-rectifying and spin-filtering effects are realized. The physical mechanism is explained by the spin-resolved bias voltage-dependent transmission spectra, the energy levels of the corresponding molecular projected self-consistent Hamiltonian orbitals, and their spatial distributions. The results demonstrate that the Blatter radical has great potential in the development of highperformance multifunctional molecular spintronic devices.
基金the National Natural Science Foundation of China(Grant No.10074075)the Department of Science and Technology under the National Key Project of Basic Research(Grant No.G1999064509).
文摘A recent theoretical estimation indicated that the NM/FI/FI/NM double spin-filter junction (DSFJ, here the NM and FI represent the nonmagnetic electrode and the ferromagnetic insulator (semiconductor) spacer, respectively) could have very high tunneling magnetoresistance (TMR) at zero bias. To meet the requirement in research and application of the magnetoresistance devices, we have calculated the dependences of tunneling magnetoresistance of DSFJ on the bias (voltage), the thicknesses of ferromagnetic insulators (semiconductors) and the average barrier height. Our results show that except its very high value, the TMR of DSFJ does not decrease monotonously and rapidly with rising bias, but increase slowly at first and decrease then after having reached a maximum value. This feature is in distinct contrast to the ordinary magnetic tunnel junction FM/NI/FM (FM and NI denote the ferromagnetic electrode and the nonmagnetic insulator (semiconductor) spacer, respectively), and is of benefit to the use of DSFJ as a magnetoresistance device.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11174214,11204192the NSAF Joint Fund Jointly set up by the National Natural Science Foundation of Chinathe Chinese Academy of Engineering Physics under Grant Nos.U1230201and U1430117
文摘We theoretically investigate the spin filtering transport of double parallel quantum wires(QWs) side-coupled to a grapheme sheet and sandwiched between two ferromagnetic(FM) leads.The dependences of the wire-graphene coupling strength,wire-wire coupling strength,as well as the spin polarization of the ferromagnetic leads are studied.It is found that the wire-graphene coupling strength tends to reduce the current and the wire-wire coupling strength can first reinforce and then decrease the current.The spin polarization strength has an enhanced(identical) effect on the current under the parallel(anti-parallel) alignment of the FM leads,which gives rise to an obvious spin-filter and tunnel magnetoresistance(TMR) effect.Our results suggest that such a theoretical model can stimulate some experimental investigations about the spin-filter devices.
