在原子力显微镜(Atomic force microscope,AFM)基础上发展起来的扫描探针显微术(Scanning probe microscope,SPM)已成为推动当今纳米科学发展的最重要技术,综述了在商用AFM平台上所发展的超高分辨压电响应力显微术(PFM)、低频高分辨扫...在原子力显微镜(Atomic force microscope,AFM)基础上发展起来的扫描探针显微术(Scanning probe microscope,SPM)已成为推动当今纳米科学发展的最重要技术,综述了在商用AFM平台上所发展的超高分辨压电响应力显微术(PFM)、低频高分辨扫描探针声学显微术(SPAM)、三倍频双探针扫描热学显微术(3ω-STh M)等先进扫描探针显微术的工作原理及其应用研究,显示了该先进扫描探针显微术在纳米结构及其与外场互作用的机电、弹性、热学、热电等综合物理特性原位表征的重要潜力。展开更多
开发具有优异综合储能特性的无铅陶瓷电容器是脉冲功率技术领域的迫切需求。相较于其他无铅储能陶瓷体系,Na Nb O_(3)(NN)陶瓷具有结构相变丰富、理论密度低、电学可调性强、轻量化发展潜力大等显著优点,因而备受关注,成为当前的研究热...开发具有优异综合储能特性的无铅陶瓷电容器是脉冲功率技术领域的迫切需求。相较于其他无铅储能陶瓷体系,Na Nb O_(3)(NN)陶瓷具有结构相变丰富、理论密度低、电学可调性强、轻量化发展潜力大等显著优点,因而备受关注,成为当前的研究热点。基于降低容忍因子稳定反铁电相和增强陶瓷弛豫性的策略,开展了NN基弛豫反铁电陶瓷的制备与储能特性研究。通过引入BiFeO_(3)和Sr(Ti_(0.85)Zr_(0.15))O_(3)成功制备了0.9[0.9NaNbO_(3)-0.1BiFeO_(3)]-0.1Sr(Ti_(0.85)Zr_(0.15))O_(3)陶瓷,相较于纯NN陶瓷(0.14 J/cm^(3)、6.39%)和0.9NaNbO_(3)-0.1BiFeO_(3)陶瓷(3.55 J/cm^(3)和70.61%),其储能特性显著提升,储能密度(Wrec)与储能效率(η)分别达到了5.22 J/cm^(3)、83.92%。其优异的储能特性源于BiFeO_(3)和Sr(Ti_(0.85)Zr_(0.15))O_(3)掺杂对陶瓷的晶粒细化、反铁电相稳定性和弛豫特性的双增强机制。同时,0.9[0.9NaNbO_(3)-0.1Bi Fe O_(3)]-0.1Sr(Ti_(0.85)Zr_(0.15))O_(3)陶瓷表现出良好的温度及频率稳定性,是一种极具应用前景的电介质储能材料。展开更多
We present observations of martensite variants and ferromagnetic domain structures of Ni_(53)Mn_(24)Ga_(23) ferromagnetic shape memory alloys with a pure tetragonal martensitic phase by using scanning electron aconsti...We present observations of martensite variants and ferromagnetic domain structures of Ni_(53)Mn_(24)Ga_(23) ferromagnetic shape memory alloys with a pure tetragonal martensitic phase by using scanning electron aconstic microscopy (SEAM) and scanning thermal microscopy (SThM).Electron acoustic images show a polycrystalline morphology with martensite variants.Direct coincidence between crystallographic martensitic twin variants and magnetic domains is found.A domain-like structure,obtained by SThM,is firstly reported,and then confirmed by magnetic force microscopy (MFM).The experimental results will be helpful for investigating the local thermal properties of ferromagnets and understanding the relationship between martensite variants and magnetic domains.展开更多
基金National High-Technology Research &Development Program of China (2007AA03Z330)National Key Development Programfor Basic Research of China(2009CB623305)+3 种基金Foundation for Innovative Research Groups of the National Natural ScienceFoundation of China (50821004)National Science Foundation of China (1077411310876041)Nanotechnology Project of Shanghai Science and Technology Committee (0852nm06900)
基金Supported by the National High-Technology Research and Development Programme of China under Grant No 2007AA03Z330, the National Natural Science Foundation of China under Grant No 10774113, and the Innovation Project of the Shanghai Institute of Ceramics （SCX-0612）.
基金Supported by the National High-Technology Research and Development Program of China under Grant No 2007AA03Z330, the National Basic Research Program of China under Grant No 2009CB623305, the Foundation for Innovative Research Groups of the National Natural Science Foundation of China under Grant No 50821004, the Nanotechnology Project of Shanghai Science and Technology Committee under Grant Nos 0852nm06900, and the National Natural Science Foundation of China under Grant Nos 50577065 and 10876041.
文摘开发具有优异综合储能特性的无铅陶瓷电容器是脉冲功率技术领域的迫切需求。相较于其他无铅储能陶瓷体系,Na Nb O_(3)(NN)陶瓷具有结构相变丰富、理论密度低、电学可调性强、轻量化发展潜力大等显著优点,因而备受关注,成为当前的研究热点。基于降低容忍因子稳定反铁电相和增强陶瓷弛豫性的策略,开展了NN基弛豫反铁电陶瓷的制备与储能特性研究。通过引入BiFeO_(3)和Sr(Ti_(0.85)Zr_(0.15))O_(3)成功制备了0.9[0.9NaNbO_(3)-0.1BiFeO_(3)]-0.1Sr(Ti_(0.85)Zr_(0.15))O_(3)陶瓷,相较于纯NN陶瓷(0.14 J/cm^(3)、6.39%)和0.9NaNbO_(3)-0.1BiFeO_(3)陶瓷(3.55 J/cm^(3)和70.61%),其储能特性显著提升,储能密度(Wrec)与储能效率(η)分别达到了5.22 J/cm^(3)、83.92%。其优异的储能特性源于BiFeO_(3)和Sr(Ti_(0.85)Zr_(0.15))O_(3)掺杂对陶瓷的晶粒细化、反铁电相稳定性和弛豫特性的双增强机制。同时,0.9[0.9NaNbO_(3)-0.1Bi Fe O_(3)]-0.1Sr(Ti_(0.85)Zr_(0.15))O_(3)陶瓷表现出良好的温度及频率稳定性,是一种极具应用前景的电介质储能材料。
基金Supported by the National Basic Research Program of China under Grant Nos 2012CB933004 and 2009CB623305the Innovative Research Groups of the National Natural Science Foundation of China under Grant No 51121064+1 种基金the Nanotechnology Project of Shanghai Science and Technology Committee(No 11nm0502800)the Innovation Project of the Shanghai Institute of Ceramics(Y21ZC4110G).
文摘We present observations of martensite variants and ferromagnetic domain structures of Ni_(53)Mn_(24)Ga_(23) ferromagnetic shape memory alloys with a pure tetragonal martensitic phase by using scanning electron aconstic microscopy (SEAM) and scanning thermal microscopy (SThM).Electron acoustic images show a polycrystalline morphology with martensite variants.Direct coincidence between crystallographic martensitic twin variants and magnetic domains is found.A domain-like structure,obtained by SThM,is firstly reported,and then confirmed by magnetic force microscopy (MFM).The experimental results will be helpful for investigating the local thermal properties of ferromagnets and understanding the relationship between martensite variants and magnetic domains.
