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排序方式: 共有222条查询结果,搜索用时 265 毫秒
71.
Lei Wang Zhaofu DuChongfei Fan Lihong XuHongping Zhang Dongliang Zhao 《Journal of Alloys and Compounds》2011,509(2):508-511
Magnetostrictive and piezoelectric laminate composites of Fe-Ga and BaTiO3 have been studied. The magnetoelectric (ME) coefficients have been characterized for the transversely magnetized and transversely polarized transverse-transverse (TT) mode. At lower frequencies, the ME voltage coefficient of the laminate was 12.5 mV/Oe. Near the natural resonant frequency (∼95 kHz) of the laminate, the ME voltage coefficient was found to be dramatically increased to 28.5 mV/Oe. In addition, the induced ME voltages were near linear functions of AC magnetic field. 相似文献
72.
Studies of the Room‐Temperature Multiferroic Pb(Fe0.5Ta0.5)0.4(Zr0.53Ti0.47)0.6O3: Resonant Ultrasound Spectroscopy,Dielectric, and Magnetic Phenomena 下载免费PDF全文
J. Schiemer M. A. Carpenter D. M. Evans J. M. Gregg A. Schilling M. Arredondo M. Alexe D. Sanchez N. Ortega R. S. Katiyar M. Echizen E. Colliver S. Dutton J. F. Scott 《Advanced functional materials》2014,24(20):2993-3002
Recently, lead iron tantalate/lead zirconium titanate (PZTFT) was demonstrated to possess large, but unreliable, magnetoelectric coupling at room temperature. Such large coupling would be desirable for device applications but reproducibility would also be critical. To better understand the coupling, the properties of all 3 ferroic order parameters, elastic, electric, and magnetic, believed to be present in the material across a range of temperatures, are investigated. In high temperature elastic data, an anomaly is observed at the orthorhombic mm2 to tetragonal 4mm transition, Tot = 475 K, and a softening trend is observed as the temperature is increased toward 1300 K, where the material is known to become cubic. Thermal degradation makes it impossible to measure elastic behavior up to this temperature, however. In the low temperature region, there are elastic anomalies near ≈40 K and in the range 160–245 K. The former is interpreted as being due to a magnetic ordering transition and the latter is interpreted as a hysteretic regime of mixed rhombohedral and orthorhombic structures. Electrical and magnetic data collected below room temperature show anomalies at remarkably similar temperature ranges to the elastic data. These observations are used to suggest that the three order parameters in PZTFT are strongly coupled. 相似文献
73.
Bilayered CoFe2O4/0.68Pb(Mg1/3Nb2/3)O3-0.32PbTiO3 nanocomposite films are successfully prepared on Pt/Ti/SiO2/Si substrate via simple sol-gel process. X-ray diffraction result reveals that there exists no chemical reaction or phase diffusion between the CoFe2O4 and 0.68Pb(Mg1/3Nb2/3)O3-0.32PbTiO3 phases. The microstructure is characterized by scanning/transmission electron microscopy (STEM). The composite thin films exhibit both strong ferroelectric and ferromagnetic responses at room temperature. The maximal magnetoelectric coupling coefficient of the nanocomposite films reaches up to 25 mV/cm Oe, occurs at a lower bias magnetic field (Hdc) of 550 Oe. 相似文献
74.
James F Scott Alina Schilling S E Rowley J Marty Gregg 《Science and Technology of Advanced Materials》2015,16(3)
We describe some unsolved problems of current interest; these involve quantum critical points in ferroelectrics and problems which are not amenable to the usual density functional theory, nor to classical Landau free energy approaches (they are kinetically limited), nor even to the Landau–Kittel relationship for domain size (they do not satisfy the assumption of infinite lateral diameter) because they are dominated by finite aperiodic boundary conditions. 相似文献
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In this work, we have studied electric field‐induced magnetization effect of multiferroic BiFeO3 (BFO) nanowires in situ using magnetic force microscopy (MFM). Changes in magnetic domain contrast have been observed in the MFM phase images under applied electric potential, which indicate local magnetoelectric (ME) coupling in the nanowires. The values of saturation and magnetization at different applied electric fields were evaluated. These results suggest that one‐dimensional multiferroic BFO nanowires are potential candidates for realizing multiferroic devices at nanoscale with unique functionalities. SCANNING 36:224–230, 2014. © 2013 Wiley Periodicals, Inc. 相似文献
78.
M. S. Tomar A. Charris-Hernández D. Barrionuevo A. Kumar 《Integrated ferroelectrics》2014,157(1):63-70
Bi3.4La0.6Ti3O12 and CoFe2O4 were synthesized by chemical solution route, and Bi3.4La0.6Ti3O12/CoFe2O4 multilayers were deposited by spin coating on Pt substrate. X-ray diffraction of multilayer structures reveals composite-like polycrystalline film. Leakage current is less than 10?5 A at electric field < 90 KV/cm and follows the Ohmic behavior. Dielectric response shows relaxation and the loss (tan δ) is below 3% at 106 Hz. Room temperature ferrroelectric polarization (Pr) = 20.2 μC/cm2 and ferromagnetic memory (Mr) = 46.5 emu/cm3 has been obtained. Co-existence of FE and FM response can be attributed to stress and different permeability and permittivity involved in multilayer structures. 相似文献
79.
Integration of Self‐Assembled Epitaxial BiFeO3–CoFe2O4 Multiferroic Nanocomposites on Silicon Substrates 下载免费PDF全文
Dong Hun Kim Nicolas M. Aimon Xue Yin Sun Lior Kornblum Fred. J. Walker Charles. H. Ahn Caroline A. Ross 《Advanced functional materials》2014,24(37):5889-5896
Perovskite‐spinel epitaxial nanocomposite thin films are commonly grown on single crystal perovskite substrates, but integration onto a Si substrate can greatly increase their usefulness in devices. Epitaxial BiFeO3–CoFe2O4 nanocomposites consisting of CoFe2O4 pillars in a BiFeO3 matrix are grown on (001) Si with two types of buffer layers: molecular beam epitaxy (MBE)‐grown SrTiO3‐coated Si and pulsed‐laser‐deposited (PLD) Sr(Ti0.65Fe0.35)O3/CeO2/yttria‐stabilized ZrO2/Si. The nanocomposite grows with the same crystallographic orientation and morphology as that observed on single crystal SrTiO3 when the buffered Si substrates are smooth, but roughness of the Sr(Ti0.65Fe0.35)O3 promoted additional CoFe2O4 pillar orientations with 45° rotation. The nanocomposites on MBE‐buffered Si show very high magnetic anisotropy resulting from magnetoelastic effects, whereas the hysteresis of nanocomposites on PLD‐buffered Si can be understood as a combination of the hysteresis of the Sr(Ti0.65Fe0.35)O3 film and the CoFe2O4 pillars. 相似文献
80.
Jae-Hyeon Cho Yu Jin Kim Su Hwan Kim Young-Jin Lee Jun-Yong Choi Geon-Tae Hwang Jungho Ryu Sang Kyu Kwak Wook Jo 《Journal of the American Ceramic Society》2022,105(4):2655-2662
A nickel–zinc ferrite system, which is one of the well-known versatile soft-ferromagnetic oxides, was investigated in terms of magnetoelectric (ME) coupling at room temperature. Herein, we demonstrated that spin canting is manipulated through a composition-induced structural transition from an inverse to a normal spinel structure, leading to modulation in the ME coupling. The ME coefficient was maximized at 60 at.% Zn substitution with a value of 0.1 mV/(Oe·cm), denoting ∼70% enhancement compared to that of the pure nickel ferrite. It was revealed that the interspin angle is enhanced along the octahedral site at up to ∼60 at.% Zn substitution, consistent with the composition level at the culmination of the ME coupling, evidenced by X-ray diffraction profiles and magnetic hysteresis loops combined with density functional theory calculations. Given that this approach is based on a tractable fabrication method, this study is expected to be widely used in modulation of the ME coupling in spinel-structured oxides. 相似文献