| 著作名稱： | H. C. Yang, L. M. Wang, J. H. Lu and H. W. Yu, “Scanning Tunneling Spectroscopy and Josephson Tunneling of High-Tc YBa2Cu3Oy Oxide Thin Films“ in “Studies of High Temperature Superconductors” edited by Anant Narlikar 20, 41 |
| 年度： | 1996 |
| 類別： |
學術專書
|
| 摘要： | |
| 關鍵字： | |
| 著作名稱： | H. C. Yang, C. H. Wu, M. J. Chen, C. H. Chen, Hsiao-Wen Yu, J. T. Jeng and H. E. Horng,”Coherence Phase Locking of High-Tc YBa2Cu3Oy Josephson Junctions”, IEEE Trans. Appl. Supercond. 11, 308 |
| 年度： | 2001 |
| 類別： |
期刊論文
|
| 摘要： | |
| 關鍵字： | |
| 著作名稱： | Jau-Han Chen, Kuen-Lin Chen, Hsiao-Wen Yu, Ming-Jye Chen, Chiu-Hsien Wu, Jen-Tzong Jeng, Herng-Er Horng, and Hong-Chen Yang, “Effect of Modulation Schemes on the Performance of Directly Coupled High-Tc dc SQUID Magmetometers”, IEEE Trans. Appl. Supercond. 11, 1110 |
| 年度： | 2001 |
| 類別： |
期刊論文
|
| 摘要： | |
| 關鍵字： | |
| 著作名稱： | Hsiao-Wen Yu, Ming-Jye Chen, H. C. Yang, S. Y. Yang, and H. E. Horng, “Effect of the grooved SrTiO bicrystal line on the YBa2Cu3Oy grain boundary “, Physica C 333,163 |
| 年度： | 2000 |
| 類別： |
期刊論文
|
| 摘要： | |
| 關鍵字： | |
| 著作名稱： | H. C. Yang, S. Y. Yang, H. E. Horng, H. W. Yu, J. H. Chen, J. T. Jeng, and H. W. Lin, “Study of High-Tc YBa2Cu3Oy SQUIDs”, Chin. J. Phys. 38. 322 |
| 年度： | 2000 |
| 類別： |
期刊論文
|
| 摘要： | |
| 關鍵字： | |
| 著作名稱： | Hsiao-Wen Yu, Ming-Jye Chen, Hong-Chang Yang, S. Y. Yang, H. E. Horng, “Characterization of Grain Boundaries in YBa2Cu3Oy Bicrystal Junctions”, IEEE Trans. Appl. Supercond. 9, 3101 |
| 年度： | 1999 |
| 類別： |
期刊論文
|
| 摘要： | |
| 關鍵字： | |
| 著作名稱： | H. C. Yang, D. C. Jou, H. W. Yu, H. E. Horng, J. H. Lu, J. M. Wu, and S. Y. Yang, “Characteristics of High-Tc YBa2Cu3Oy Junctions and SQUIDs“, Chin.J.Phys. 36, 401 |
| 年度： | 1998 |
| 類別： |
期刊論文
|
| 摘要： | |
| 關鍵字： | |
| 著作名稱： | H. C. Yang, H. W. Yu, C. C. Kuo, H. E. Horng, and S.Y. Yang, “Scanning Tunneling Spectroscopy on YBa2Cu3Oy/PrBa2Cu3Oy/YBa2Cu3Oy Sandwiched Junctions and YBa2Cu3Oy/Y0.5Pr0.5Ba2Cu3Oy/YBa2Cu3Oy Superlattices“, Physica C 282-287, 2443 |
| 年度： | 1997 |
| 類別： |
期刊論文
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| 摘要： | |
| 關鍵字： | |
| 著作名稱： | H. C. Yang, H. W. Yu, H. E. Horng, and F. F. Lin, “Mixed-state Properties of YBa2Cu3Oy/Nd1.85Ce0.15CuO4 and YBa2Cu3Oy/Y0.5Pr0.5Ba2Cu3Oy Mutilayers”, Physica C 282-287,1143 |
| 年度： | 1997 |
| 類別： |
期刊論文
|
| 摘要： | |
| 關鍵字： | |
| 著作名稱： | H. C. Yang, B. Young, Y. F. Jian, H. W. Yu, and H. E. Horng, “Scanning Tunneling Spectroscopy of YBa2Cu3Oy Films and M/YBa2Cu3Oy Thin Films“, Chin. J. Phys. 34, 611 |
| 年度： | 1996 |
| 類別： |
期刊論文
|
| 摘要： | |
| 關鍵字： | |
| 著作名稱： | Hsin-Yi Chen, Y. D. Yao, H. W. Yu, H. M. Cho, L. M. Wang, H. C. Yang, and H. E. Horng, “Effect of Transport Current Density on the Longitudinal and Hall Resistivities in the Mixed State of YBCO Films“ Chin. J. Phys. 34, 588 |
| 年度： | 1996 |
| 類別： |
期刊論文
|
| 摘要： | |
| 關鍵字： | |
| 著作名稱： | L. M. Wang, H. W. Yu, H. C. Yang, and H. E. Horng, “Optimum Sputtering Conditions on the in-situ Growth of superconducting YBa2Cu3Oy Films with an Off-axis RF Sputtering configuration”, Physica C 256,57 |
| 年度： | 1996 |
| 類別： |
期刊論文
|
| 摘要： | |
| 關鍵字： | |
| 著作名稱： | Influence of Sintering Time on Complex Permeability for Polycrystalline La0.7Sr0.3MnO3 Manganite |
| 年度： | 2016 |
| 類別： |
期刊論文
International Journal of Science and Engineering
|
| 摘要： | Recently, peroviskite manganite La0.7Sr0.3MnO3 (LSMO) has spurred lots of research excitement due to the exhibition of low-field giant magnetoimpedance (GMI) effect. Since the GMI effect for mangnites originates mainly from the magnetic-field-induced change of complex permeability, we have fabricated LSMO toroidal inductors with different sintering time to investigate the field-induced behavior of complex permeability. All the measured spectra show relaxation character due to domain wall displacement. As the sintering time increases, the permeability increases; however, the resonance frequency fr and quality factor (Q factor) decreases. Under applied magnetic field Bdc, the permeability decreases. A giant field-induced change ratio of the real part for complex permeability μ′/μ′ of 84, 86 and 85 at 50 kHz, 40 kHz and 30 kHz are obtained under a very small field Bdc 450 G for the 8 hr, 16 hr and 24 hr sintering samples. Besides, a huge field-induced change ratio of the imaginary part for complex permeability μ′′/μ′′ of 94, 94 and 93 at 260 kHz, 260 kHz and 160 kHz are found under Bdc 450 G for the 8 hr, 16 hr and 24 hr sintering samples. The value of fr increases with Bdc and a linearly dependence between fr and Bdc is observed above 50 G. Our measured results are useful in understanding the GMI behavior of LSMO manganites and fabrication of LSMO magnetometers. |
| 關鍵字： | La0.7Sr0.3MnO3, complex permeability, sintering time, resonance frequency, domain wall displacement |
| 著作名稱： | 燒結溫度對鑭鍶錳氧複數磁導率的影響 |
| 年度： | 2016 |
| 類別： |
會議論文
|
| 摘要： | 本實驗製作不同燒結溫度的鑭鍶錳氧塊材，探討其複數磁導率特性。研究結果顯示，最高溫度攝氏1350度燒結的樣品磁導率最大，電阻率最低，卻因磁滯損耗與渦電流損耗增加而導致品質因子下降。當燒結溫度降低至攝氏1200度，晶粒尺度與磁導率大幅減少，共振頻率與品質因子急遽增加。1200度樣品的磁導率約為1350度樣品的一半，共振頻率約為五倍，品質因子最大值則為1.67倍。我們發現磁導率的變化與晶粒大小有關，共振頻率的改變則與晶粒尺度、電阻率與靜磁導率有關。 |
| 關鍵字： | 鑭鍶錳氧、複數磁導率、燒結溫度、共振頻率、品質因子 |
| 著作名稱： | La0.7Sr0.3MnO3 Toroidal Inductor for Low Magnetic Field Sensing |
| 年度： | 2016 |
| 類別： |
會議論文
|
| 摘要： | La0.7Sr0.3MnO3 (LSMO) toroidal inductors sintered at 1300C for various sintering time have been fabricated for magnetic field sensing. The complex permeability spectra show relaxation character due to domain wall displacement. As the sintering time increases, the permeability increases and the resonance frequency fr decreases. Under applied magnetic field, the permeability decreases and fr increases. Large shift of fr by low fields was observed. The 8 hr sintering sample exhibits a best magnetic field to frequency transfer ratio of 5.13 kHz/G. Our measured results indicate that LSMO is a promising material for the design and fabrication of low-cost magnetic field sensors. |
| 關鍵字： | complex permeability, resonance frequency, La0.7Sr0.3MnO3, magnetic field sensor |
| 著作名稱： | Giant Magnetoimpedance in La0.7Sr0.3MnO3 Manganite Prepared by Sol–gel Method |
| 年度： | 2011 |
| 類別： |
會議論文
|
| 摘要： | The resistance and reactance of the magnetoimpedance of ferromagnetic manganite La0.7Sr0.3MnO3 prepared by sol–gel method have been measured at room temperature over a frequency interval from 100 kHz to 10 MHz and in the presence of different dc bias magnetic field (Hdc 0-300 Oe). The manganite La0.7Sr0.3MnO3 shows a magnetoreactance X/X0 of 39.6% at 400 kHz, a giant magnetoimpedance Z/Z0 of 31.9% at 3 MHz and a giant ac magnetoresistance R/R0 of 45.9% at 7 MHz under a very low magnetic field of 300 Oe. The sample also exhibits a giant magnetoreactance X/X0 of about 38% in a wide frequency range of 200 kHz to 1 MHz under a longitudinal magnetic field 300 Oe. The value of low-field magnetoreactance, magnetoimpedance and ac magnetoresistance are larger than those of traditional sintered manganites. These effects are attributed to the magnetic inhomogeneity mainly due to the grain boundary. |
| 關鍵字： | Magnetoimpedance; manganite; magnetic inhomogeneity |
| 著作名稱： | Magnetoimpedance Effect in K-doped La0.7Sr0.3MnO3 under Low Magnetic Fields |
| 年度： | 2011 |
| 類別： |
會議論文
|
| 摘要： | We have studied the magnetoreactance, magnetoimpedance and magnetoresistance of La0.7Sr0.3xKxMnO3 (x 0, 0.05, 0.1 and 0.15) at room temperature over a frequency interval from 100 kHz to 10 MHz and in the presence of different dc bias magnetic field up to 300 Oe. The increase of doping level lowers the Curie temperature TC and the metal-insulator transition temperature TP. The electrical and magnetotransport characteristics are very similar for those samples with TP much higher than room temperature (RT). However, peaks and valleys occur at low frequencies in electrical measurements for the sample with TP near RT. The inductive-like behavior at the reactance valley is almost completely suppressed under a very low field of 300 Oe, resulting in a colossal magnetoreactance phenomenon. The bound-carrier transport process and capacitive-like behavior are shown at high frequencies in electrical measurements for the sample with TP lower than RT. The disappearance of the magnetoimpedance effect is connected to its semiconductor characteristic. |
| 關鍵字： | magnetoreactance; magnetoimpedance; magnetoresistance; K-doped La0.7Sr0.3MnO3 |
| 著作名稱： | J.-H. Chen*, Y.-P. Fang, L.-M. Wang, H.-H. Sung, C.-Y. Chang, B.-W. Huang, Y.-C. Chen, and H. -W. Yu, “Fabrication of high-transition-temperature superconducting quantum interference devices with ion damage Josephson junctions”, 2006 Applied Superconductivity Conference, Seattle, Washington, USA, August 27 to September 1, 2006. |
| 年度： | 2006 |
| 類別： |
會議論文
|
| 摘要： | |
| 關鍵字： | |
| 著作名稱： | H.C. Yang, J.H. Lu, H.W. Yu, D.C. Jou, H.E. Horng, J.M. Wu, and S.Y.
Yang, "Magnetic Fields Characteristics of High-Tc YBa2Cu3Oy SQUIDs," in
Proceedings of EUCAS 1997, the Third European Conference on Applied
Superconductivity, Netherlands, June 30 - July 3, 1997, p. 639. |
| 年度： | 1997 |
| 類別： |
會議論文
|
| 摘要： | |
| 關鍵字： | |
| 著作名稱： | La0.7Sr0.3MnO3與La0.7Sr0.25K0.05MnO3在外加磁場下複數磁導率的特性研究 |
| 年度： | 2021 |
| 類別： |
會議論文
|
| 摘要： | 本實驗探討在外加直流磁場下，La0.7Sr0.3MnO3與La0.7Sr0.25K0.05MnO3的複數磁導率行為，並期許摻雜鉀元素能夠提升樣品鬆弛頻率在外加磁場下的變化量。研究結果顯示，與La0.7Sr0.3MnO3相比，La0.7Sr0.25K0.05MnO3的磁導率較小，電阻率較大，鬆弛頻率增加。La0.7Sr0.25K0.05MnO3在磁場下鬆弛頻率變化的提升，與電阻率增加有關。詳細研究結果將在內文中討論。 |
| 關鍵字： | La0.7Sr0.3MnO3、複數磁導率、鬆弛頻率 |
| 著作名稱： | La0.7Sr0.3-xKxMnO3的相變特性研究 |
| 年度： | 2021 |
| 類別： |
會議論文
|
| 摘要： | 本實驗探討La0.7Sr0.3-xKxMnO3(0 x 0.15)塊材於300 K到390 K的溫度區間，在10 kHz量測到的複數磁導率μ μ′ jμ′′及直流電阻率相變特性。樣品以固態反應法製作，最終燒結溫度為1300°C。利用漆包線纏繞環狀樣品量測磁導率，利用切割錠狀樣品成長條狀量測直流電阻率。SEM影像顯示，樣品晶粒尺度隨摻雜濃度x變化不大。而隨著x提高，樣品磁導率下降，電阻率升高。當溫度提升，樣品的μ′與μ′′值皆顯現鐵磁到順磁的相轉變特性。隨著x增加，居禮溫度TC由x 0的371 K降低至x 0.15的343 K。直流電阻率在TC附近顯現對應的金屬-半導體相轉變，相變溫度較TC略低，原因是當鐵磁態的樣品若要形成導體，自旋偏極化電子還需克服晶界接面所形成的能障。詳細研究結果將在內文中討論。 |
| 關鍵字： | La0.7Sr0.3-xKxMnO3、複數磁導率、居禮溫度 |
| 著作名稱： | La0.7Sr0.3MnO3複數磁導率在磁場下的特性研究 |
| 年度： | 2020 |
| 類別： |
會議論文
|
| 摘要： | 本實驗製作La0.7Sr0.3MnO3塊材，量測其磁導率與電阻率對溫度的關係，並探討在外加磁場下複數磁導率的變化行為。樣品隨溫度升高顯現鐵磁到順磁與金屬到半導體的相轉變。隨外加磁場增加，磁導率減少，鬆弛頻率增加。磁導率對頻率的關係，可用單域內磁域旋轉與多域內磁壁位移兩項相加而得，其中磁壁位移為主要貢獻。由於樣品電阻率很小，渦電流阻滯為磁壁位移主要阻滯來源，磁壁位移鬆弛頻率與公式計算出之數值大致相符。 |
| 關鍵字： | La0.7Sr0.3MnO3、複數磁導率、鬆弛頻率、磁壁位移、磁域旋轉 |
| 著作名稱： | 摻雜鉀對鑭鍶錳氧電感型磁量計性能的影響 |
| 年度： | 2019 |
| 類別： |
會議論文
|
| 摘要： | 本實驗研究La0.7Sr0.3-xKxMnO3複數磁導率鬆弛頻率在外加磁場下的變化，利用這個特性製作磁量計，並希望摻雜鉀可提升磁量計的靈敏度。當摻雜濃度從零變化至0.1，磁場對頻率轉換率由0.28 kHz/G增加為4.19 kHz/G。轉換率的提升應主要來自於樣品電阻率的增加。詳細研究成果將在內文中討論。 |
| 關鍵字： | 鑭鍶錳氧、磁量計、複數磁導率、鬆弛頻率 |
| 著作名稱： | La0.7Sr0.3-xKxMnO3的複數磁導率特性研究 |
| 年度： | 2019 |
| 類別： |
會議論文
|
| 摘要： | 本實驗製作不同摻雜濃度的La0.7Sr0.3-xKxMnO3塊材，探討其電阻率與複數磁導率特性。研究結果顯示，沒有摻雜鉀的樣品磁導率最高，電阻率最小，卻因磁滯損耗與渦電流損耗導致品質因子下降。當摻雜濃度增加，樣品磁導率減少，鬆弛頻率增加，品質因子提升。最大摻雜濃度(x 0.15)與未摻雜(x 0)的樣品相較，靜磁導率約降低四分之一，鬆弛頻率增加11倍，品質因子最大值增加2倍。磁導率的減少及電阻率的增加與異價錳離子間雙交換作用降低及eg電子遷移率下降有關，而磁導率減少及電阻率增加導致鬆弛頻率提高。詳細研究結果將在內文中討論。 |
| 關鍵字： | La0.7Sr0.3-xKxMnO3、複數磁導率、鬆弛頻率、品質因子 |
| 著作名稱： | 摻雜鉀對鑭鍶錳氧室溫磁阻及複數磁導率的影響 |
| 年度： | 2018 |
| 類別： |
會議論文
|
| 摘要： | 本實驗製作燒結溫度1200C的La0.7Sr0.3MnO3 及La0.7Sr0.25K0.05MnO3塊材，研究摻雜鉀對La0.7Sr0.3MnO3室溫磁阻與磁導率的影響。研究結果顯示，摻雜鉀可有效提升電阻率與室溫磁阻，在2000 G的磁場下，磁阻提高了50%。另外，摻雜鉀會造成磁導率降低，品質因子增加，但由於從La0.7Sr0.25K0.05MnO3磁譜中不易觀察到磁壁位移鬆弛頻率f_dw^r，所以無法將其作為磁量計。摻雜鉀造成的結構不均質、異價錳離子間雙交換作用的降低及eg電子遷移率的下降，都與電阻率及磁阻的增加有關。雙交換作用降低也造成La0.7Sr0.25K0.05MnO3的磁導率減少。電阻率較小的La0.7Sr0.3MnO3因磁滯損耗與渦電流損耗較高，品質因子反而降低。 |
| 關鍵字： | 鑭鍶錳氧、磁阻、複數磁導率、鬆弛頻率、品質因子 |
| 著作名稱： | TiO2塊材的介電特性研究 |
| 年度： | 2018 |
| 類別： |
會議論文
|
| 摘要： | 本實驗探討TiO2塊材變化溫度的複數介電常數ϵ ϵ′ jϵ′′及複數電模數M M′ jM′′對頻率的關係。研究結果顯示，樣品低溫時的極化與電子在異價鈦間的短程躍遷有關。當溫度升高，氧空缺長程遷徙造成的空間電荷極化導致樣品介電常數大幅增加。低溫時ϵ′對ϵ′′的Cole-Cole圖形成一與晶粒內極化有關的半圓，當溫度升高，另一個與晶界接面有關的半圓會出現。藉由鬆弛頻率對溫度的關係，可得出侷域化電子由Ti3躍遷到Ti4所需之活化能。 |
| 關鍵字： | TiO2、介電常數、電模數、鬆弛頻率、Cole-Cole |
| 著作名稱： | Investigation of the Resonance Frequency of Complex Permeability for Polycrystalline Perovskite La0.7Sr0.3MnO3 |
| 年度： | 2016 |
| 類別： |
會議論文
|
| 摘要： | The resonance frequency fr of complex permeability for polycrystalline La0.7Sr0.3MnO3 toroidal inductors with different thickness and sintering time have been investigated under various applied magnetic fields. The measured spectra exhibit pronounced dispersions with relaxation character which can be discussed on the basis of domain wall displacement. The magnitude of fr decreases with sample thickness. As the temperature increases from 300 K, fr remains constant at first, but then abruptly increases around the Curie temperature TC due to the increase of permeability. The magnitude of fr decreases with sintering time due to the increase of permeability and decrease of resistivity. The increase of wall stiffness is responsible for the increase of fr under applied magnetic field. The sample with minimum thickness, smallest grain size and largest resistivity exhibits the best magnetic field to frequency transfer ratio of 5.13 kHz/G. The eddy current damping is the main damping factor of wall displacement and there is an excellent agreement of observed and calculated fr value. The results are useful in promoting the performance of LSMO magnetometer. |
| 關鍵字： | La0.7Sr0.3MnO3, complex permeability, resonance frequency, eddy current damping, wall displacement |
| 著作名稱： | Temperature Dependence of Complex Permeability in Polycrystalline Perovskite La0.7Sr0.3MnO3 |
| 年度： | 2016 |
| 類別： |
會議論文
|
| 摘要： | The temperature-dependent resistivity and complex permeability of polycrystalline La0.7Sr0.3MnO3 have been investigated from 300 to 380 K. The magnitude of resistivity is very small and of the order of mcm. The value of increases with temperature and the metal-insulator transition temperature TP was about 362 K determined from the maximum curvature on the (T) curve. There is a pronounced dispersion of the relaxation in the measured spectra due to domain wall displacement. The magnitude of complex permeability increases with temperature, reaches its maximum value around the Curie temperature TC then abruptly drops。As the temperature increases, the resonance frequency fr remains a constant value of about 1.4 MHz then increases rapidly above TC due to the decrease of permeability. The agreement of observed and calculated fr proves the assumption that the damping of wall displacement is mainly attributed to the eddy current. The results are discussed |
| 關鍵字： | La0.7Sr0.3MnO3, complex permeability, resonance frequency, wall displacement |
| 著作名稱： | 以溶膠凝膠法備製的鑭鍶錳氧塊材之磁阻抗效應研究 |
| 年度： | 2016 |
| 類別： |
會議論文
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| 摘要： | 本實驗以溶膠凝膠法製作多晶鑭鍶錳氧塊材，探討其室溫的磁阻抗效應。由於晶粒尺度很小，樣品的電阻率高出一般以固態反應法製作的多晶塊材三個數量級，所以集膚效應很弱，要到相當高的頻率才能出現明顯的磁阻抗量值。在450 G的外加磁場下，樣品可於10 MHz量測到最大的磁阻抗-2.27%，12 MHz量測到最大的磁電阻-2.17%，3 MHz量測到最大的磁電抗-6.84%。詳細的研究結果將在內文中討論。 |
| 關鍵字： | 鑭鍶錳氧、溶膠凝膠法、磁阻抗、集膚效應 |
| 著作名稱： | 溶膠凝膠法備製的鑭鍶錳氧多晶塊材之磁性與電性研究 |
| 年度： | 2016 |
| 類別： |
會議論文
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| 摘要： | 本實驗以溶膠凝膠法製作多晶態鑭鍶錳氧塊材，探討表面形貌、結晶性、磁阻效應及複數磁導率μ μ′ + jμ′′之間的關係。樣品在室溫下呈現磁性與負阻效應，負阻值與溶膠凝膠薄膜相較略為提升。樣品的晶粒尺度很小，電阻率高出一般以固態反應法製作的多晶塊材三個數量級，磁導率則減為三分之一。量測到的磁譜皆顯現出與磁壁位移有關的色散特性，由於本值阻滯為磁壁位移的主要阻滯來源而非渦電流阻滯，共振頻率fr隨外加磁場Bdc減少。因為fr與Bdc間沒有線性關係，樣品不適合做磁場感測器。詳細的研究結果將在內文中討論。 |
| 關鍵字： | 鑭鍶錳氧、溶膠凝膠法、磁阻、複數磁導率、共振頻率 |
| 著作名稱： | 燒結溫度對鑭鍶錳氧電感型磁量計性能的影響 |
| 年度： | 2016 |
| 類別： |
會議論文
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| 摘要： | 本實驗利用變化燒結溫度來提升鑭鍶錳氧電感型磁量計的磁場對頻率轉換率。當燒結溫度由攝氏1350度降低至攝氏1200度，轉換率由60 Hz/G 增加為500 Hz/G，約提高733%。由於樣品的電阻率變化不大，轉換率的增加應來自於晶粒尺度的大幅減小，詳細的研究成果將在內文中討論。 |
| 關鍵字： | 鑭鍶錳氧、磁量計、複數磁導率、燒結溫度、共振頻率 |
| 著作名稱： | Correlation between magnetoimpedance and permeability in Polycrystalline Perovskite La0.7Sr0.3MnO3 |
| 年度： | 2015 |
| 類別： |
會議論文
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| 摘要： | The giant magnetoimpedance effect and permeability change of La0.7Sr0.3MnO3 mangnite have been studied to investigate their correlation. All the value of ac resistance R, reactance X, impedance Z, transverse real permeability μt′ and transverse imaginary permeability μt〃 decrease with increasing field. The rectangular shaped La0.7Sr0.3MnO3 sample exhibits a huge ac magnetoresistance R/R0 40 at 3MHz, a large magnetoreactance X/X0 20 at 100 kHz and a giant magnetoimpedance Z/Z0 18.8 at 500 kHz under a low field Hdc 450 Oe at room temperature. The magnetic spectra of La0.7Sr0.3MnO3 toroid show relaxation character due to domain wall displacement. The resonance frequency of magnetic spectra increases with the applied magnetic field. A huge magnetic-field-induced change ratio Dμt′/μt′ -34% at 10 kHz and Dμt〃/μt〃 -53% at 300 kHz are found under a very low field of 450 Oe at room temperature. Under applied magnetic fields, both the value of R/R0 and Dμt〃/μt〃 increase with frequency, undergo a maximum and then decrease, while both the value of X/X0 and Dμt′/μt′ monotonically decrease with frequency. Our measured results indicate that R/R0 is mainly correlated to Dμt〃/μt〃, while X/X0 is mainly dominated by Dμt′/μt′. The giant magnetoimpedance effect of La0.7Sr0.3MnO3 mangnite is attributed to the change of transverse permeability. |
| 關鍵字： | magnetoimpedance, transverse permeability, La0.7Sr0.3MnO3 |
| 著作名稱： | Microstructure and magneto-transport property of La0.7Sr0.3MnO3 |
| 年度： | 2015 |
| 類別： |
會議論文
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| 摘要： | The microstructure, electrical and magneto-transport properties of La0.7Sr0.3MnO3 bulk have been studied. The SEM photograph displays the polycrystalline character of the sample. From the measured temperature-dependant resistivity, the metal-insulator phase transition temperature Tp is determined to be 380 K. The resistivity decreases under an applied magnetic field of 0.2 T, showing the negative magnetoresistivity behavior. As the temperature increases, the magnetoresistance ratio MR increases, undergoes its maximum value of 6.5% around Tp, and then abruptly decreases in the insulator region. The frequency-dependant room temperature impedance was also investigated. The impedance is largely suppressed under applied magnetic fields, which exhibits the giant magnetic impedance phenomenon. Under a bias magnetic field Hdc 500 Oe, a giant magnetoimpedance ratio of 18.7% at 700 kHz and a large ac magnetoresistance ratio of 42.2% at 3 MHz are found. The huge low-field ac magnetoresistance reported in this work can be exploited for magnetic field sensor. |
| 關鍵字： | La0.7Sr0.3MnO3, microstructure, magneto-transport property |
| 著作名稱： | Investigation of the Complex Permeability for Polycrystalline Perovskite La0.7Sr0.3MnO3 |
| 年度： | 2014 |
| 類別： |
會議論文
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| 摘要： | The frequency-response complex permeability of La0.7Sr0.3MnO3 toroids with thickness range from 1 to 3 mm has been investigated over an interval from 100 kHz to 10 MHz and in the presence of different dc magnetic field. The magnetic spectra can be discussed on the basis of domain wall displacement. The shift of resonance frequency with sample thickness is attributed to the demagnetizing effect. The increase of wall stiffness is responsible for the increase of resonance frequency under applied magnetic field. Larger field-induced reduction of permeability is found for the thinner sample. Our results indicate that the sample geometry is an important factor in analyzing the permeability spectra of ferromagnetic oxide. |
| 關鍵字： | complex permeability, domain wall displacement, geometry effect, demagnetizing effect |
| 著作名稱： | Ac magnetotransport property of sol-gel La0.7Sr0.3MnO3 manganite |
| 年度： | 2014 |
| 類別： |
會議論文
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| 摘要： | We investigate the ac resistance R and inductive reactance X of sol-gel La0.7Sr0.3MnO3 at various temperatures under magnetic field. Huge ac magnetoresistance deltaR/R0 of 61% at 5 MHz and magnetoreactance deltaX/X0 of -68% at 0.5 MHz are found in a very small field of Hdc 300 Oe. Both the deltaR/R0 and deltaDX/X0 values are much larger than those of traditional sintered manganites. The results are discussed. |
| 關鍵字： | magnetotransport; ac magnetoresistance; magnetoreactance; La0.7Sr0.3MnO3 |
| 著作名稱： | Study of the magnetoresistance and magnetoimpedance for La0.7Sr0.3MnO3 Manganite |
| 年度： | 2014 |
| 類別： |
會議論文
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| 摘要： | We have investigated the crystal structure, electrical property, magnetoresistance and magnetoimpedance of La0.7Sr0.3MnO3 manganite. The temperature-dependant resistivity was measured in the temperature interval of 300 to 410K. The phase-transition temperature Tp of resistivity is about 380 K. Under an applied field of 0.2 T, the resistivity decreases. The magnetoresistance ratio increases with temperature and shows a peak value of 6.5% around Tp. The room-temperature impedance and magnetoimpedance were also measured for various frequencies. A giant magnetoimpedance ratio of 18.7% at 700 kHz and a large ac magnetoresistance ratio of 42.2% at 3 MHz under a very low field of 500 Oe are found. The results are discussed. |
| 關鍵字： | La0.7Sr0.3MnO3, magnetoresistance, magnetoimpedance |
| 著作名稱： | Thickness Dependence of Complex Permeability in Polycrystalline Perovskite La0.7Sr0.3MnO3 |
| 年度： | 2013 |
| 類別： |
會議論文
|
| 摘要： | The frequency-response complex permeability of La0.7Sr0.3MnO3 toroids with thickness range from 1 to 3 mm has been investigated over an interval from 100 kHz to 10 MHz and in the presence of different dc magnetic field. The magnetic spectra can be discussed on the basis of domain wall displacement. The shift of resonance frequency with sample thickness is attributed to the demagnetizing effect. The increase of wall stiffness is responsible for the increase of resonance frequency under applied magnetic field. Larger field-induced reduction of permeability is found for the thinner sample. Our results indicate that the sample geometry is an important factor in analyzing the permeability spectra of ferromagnetic oxide. |
| 關鍵字： | complex permeability, domain wall displacement, geometry effect, demagnetizing effect |
| 著作名稱： | Huge low-field ac magnetoresistance in sol-gel prepared La0.7Sr0.3MnO3 manganite |
| 年度： | 2012 |
| 類別： |
會議論文
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| 摘要： | |
| 關鍵字： | |
| 著作名稱： | Huge low-field magnetoreactance in sol-gel prepared La0.7Sr0.3MnO3 manganite |
| 年度： | 2012 |
| 類別： |
會議論文
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| 摘要： | |
| 關鍵字： | |
| 著作名稱： | 燒結溫度對鑭鍶錳氧塊材物性的影響 |
| 年度： | 2012 |
| 類別： |
會議論文
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| 摘要： | 本實驗使用不同溫度燒結鑭鍶錳氧塊材，並研究其結構、電性及磁阻特性。XRD圖及SEM圖中顯示，較高的燒結溫度會使塊材有好的結晶性，並促成晶粒成長。我們並探討塊材在300K至410K的溫度區間內，電阻率及磁阻對溫度的關係。 |
| 關鍵字： | |
| 著作名稱： | Influence of Sintering Temperature on the Magnetoimpedance Effect of La0.7Sr0.3MnO3 Manganite |
| 年度： | 2011 |
| 類別： |
會議論文
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| 摘要： | We have investigated the effects of sintering temperature on the crystal structure and magnetoimpedance (MI) effect of La0.7Sr0.3MnO3 manganites. Two polycrystalline samples prepared by the solid-state reaction method were studied, with final sintered temperatures of 1200 C and 1300 C. The sample sintered at higher temperature exhibits an improved crystallinity and a reduced resistivity. It also shows stronger skin effect and larger magnetoimpedance at lower frequency. A giant MI ratio of 18.7% at 700 kHz and a large ac magnetoresistance of 42.2% at 3 MHz could be obtained under a very low field of 500 Oe for the sample sintered at 1300 C. |
| 關鍵字： | sintering temperature, magnetoimpedance, skin effect, manganite |
| 著作名稱： | 矽(100)基材上La0.7Sr0.3MnO3 多晶溶膠-凝膠薄膜之傳輸特性 |
| 年度： | 2010 |
| 類別： |
會議論文
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| 摘要： | 我們利用溶膠-凝膠法於矽(100)基材上製作一系列不同退火溫度的多晶La0.7Sr0.3MnO3薄膜。研究顯示薄膜出現無擇優取向之菱方晶系結構，且退火溫度會影響其結晶性。在室溫外加磁場0.2 T下，退火溫度為800 °C的薄膜有最佳的磁阻率0.84。這個現象與自旋偏極化電子於晶粒間的穿隧行為有關，驗證了晶界接面在低場磁阻的重要性。 |
| 關鍵字： | 龐磁阻、溶膠-凝膠薄膜、退火溫度、晶界接面、低場磁阻 |
| 著作名稱： | *Hsiao-Wen Yu(尤孝雯) J. G. Lin(林昭吟) “Enhanced colossal magnetoresistance near room temperature in the phase-separation La0.7Sr0.3-xKxMnO3”，中國材料科學學會2008年年會，台北科技大學，97年11月21日至22日。 |
| 年度： | 2008 |
| 類別： |
會議論文
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| 摘要： | |
| 關鍵字： | |