http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Microwire Magneto-Resonance Characteristics in a Magnetic LC-Resonator Device
유성초,Anh-Tuan Le,Quang Hoa Nguyen,이희복 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.3
In the present work, the magneto-resonance characteristics in a LC-resonator device built on amorphous glass-coated Co-based ferromagnetic microwires have been investigated. The giant magnetoimpedance (GMI) measurements were conducted in the high-frequency range of 100 { 800 MHz and for a dc magnetic field varying within 120 Oe. The variation in the diameter of the microwire had significant effects on the magnitude of the GMI effect, the characteristic resonance frequencies and the positions of the resonant peaks. The resonance in a LC-resonator device occurs at a specific intensity of the applied dc magnetic field. Noticeably, the largest field sensitivity of the GMI reaches extremely high values of 20,000 %/Oe and 18,000 %/Oe at resonance frequencies of 518.21 MHz and 146.25 MHz for LC-resonators constructed using Co83.2B3.3Si5.9Mn7.6 and Co67Fe3.8Ni1.4B11.5Si14.6Mo1.7 microwires, respectively. These results are of great interest for developing a new class of ultra-sensitives, high-frequency GMI-based magnetic sensors.
유성초,Quang Hoa Nguyen,Anh-Tuan Le,Chau Nguyen,이희복 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.3
In this leter, a systematic study of the giant magnetoimpedance (GMI) effect in nanostructured Fe-rich composite materials reported. The nanostructure of Fe-rich composite materials consisting of ultra-fine nanoscale Fe(Si) grains embedded in a residual amorphous matrix was atained by annealing their amorphous precursors at a proper temperature (∽550 ℃). The impedance mea- surements were conducted in the frequency range of 1 - 10 MHz for a dc magnetic field varying within 300 Oe. We demonstrated that the nanocrystalization of the aloys led to an improved magnetic softnes of the material and, hence, to the GMI effect. It was obvious that, at low frequencies (f ≤ 4 MHz), the maximum value of GMI was observed at near zero field (Hdc ∽ 0) and the GMI profiles exhibited a typical single-peak feature. At high frequencies (f ≥ 5MHz), however, a two-peak feature was observed. More interestingly, the GMI ratio and its field sensitivity reached the highest values of 170 % and 64 %/Oe at a frequency of 2 MHz, respectively. This result is very beneficial for developing highly sensitive GMI sensor applications. The observed GMI features in nanostructured Fe-rich composite materials can be interpreted by adapting the skin-effect modelin conjunction with the magnetic-field dependence of the longitudinal permeability.