We report the acoustic imaging frequency dynamics of ferroelectric domains by low-frequency acoustic probe microscopy based on the commercial atomic force microscopy. It is found that ferroelectric domain could be fir...We report the acoustic imaging frequency dynamics of ferroelectric domains by low-frequency acoustic probe microscopy based on the commercial atomic force microscopy. It is found that ferroelectric domain could be firstly visualized at lower frequency down to 0.5 kHz by AFM-based acoustic microscopy. The frequency-dependent acoustic signal revealed a strong acoustic response in the frequency range from 7kHz to 10 kHz, and reached maximum at 8.1 kHz. The acoustic contrast mechanism can be ascribed to the different elastic response of ferroelectric microstructures to local elastic stress fields, which is induced by the acoustic wave transmitting in the sample when the piezoelectric transducer is vibrating and exciting acoustic wave under ac electric fields due to normal piezoelectric effects.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）.
文摘We report the acoustic imaging frequency dynamics of ferroelectric domains by low-frequency acoustic probe microscopy based on the commercial atomic force microscopy. It is found that ferroelectric domain could be firstly visualized at lower frequency down to 0.5 kHz by AFM-based acoustic microscopy. The frequency-dependent acoustic signal revealed a strong acoustic response in the frequency range from 7kHz to 10 kHz, and reached maximum at 8.1 kHz. The acoustic contrast mechanism can be ascribed to the different elastic response of ferroelectric microstructures to local elastic stress fields, which is induced by the acoustic wave transmitting in the sample when the piezoelectric transducer is vibrating and exciting acoustic wave under ac electric fields due to normal piezoelectric effects.
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.
