Low Magnetic Field Response of 2d-Array of Weakly Coupled Ferromagnets

1999 ◽  
Vol 574 ◽  
Author(s):  
Z. G. Ivanov ◽  
R. A. Chakalov ◽  
T. Claeson
Keyword(s):  
Magnetic Field ◽  
Grain Boundaries ◽  
Buffer Layer ◽  
Seed Layer ◽  
Substrate Surface ◽  
X Ray Diffraction ◽  
Weakly Coupled ◽  
Field Response ◽  
Low Magnetic Field ◽  
2D Array

AbstractWe demonstrated a low magnetic field response in 2D array of weakly coupled ferromagnets created by bi-epitaxial growth of La0.7Sr0.3MnO3 film on multilayer template of MgO seed and CeO2 buffer layer deposited on SrTiO3 substrate. To form the array we etched the MgO seed layer into a chess board pattern. The chess board fields, where the substrate surface is disclosed, initiate a 45° in-plate rotated growth of the CeO2 buffer layer while it does not rotate on the neighboring fields covered by MgO seed layer. The La0.7Sr0.3MnO3 film inherits the template orientation of the buffer layer forming misoriented at 45° domains and a well defined 2D array of 45° grain boundaries is created. The size of the domains, correspondingly the number of grain boundaries, can be varied by changing the dimensions of the chess board fields. The multilayer structures were investigated by θ–2θ and φ-scan x-ray diffraction. A magnetoresistance of 25% by 0.5 T was measured and ascribed to the properties of the 2D array of grain boundaries.

MAGHETOTHERMO POWER OF ZnO FILMS

2005 ◽  
Vol 19 (01n03) ◽  
pp. 651-653
Author(s):  
W. L. WANG ◽  
L. LI ◽  
K. J. LIAO ◽  
J. ZHANG ◽  
R. J. ZHANG ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thermoelectric Power ◽  
Substrate Surface ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
X Ray ◽  
Increasing Temperature ◽  
The Magnetic Field ◽  
Orientation Growth

The Magnetothermoelectric and thermoelectric power of nano- ZnO films was investigated. The ZnO films in this study were prepared by DC reactive sputtering using a Zn target (99.99%) containing AL of 1.5%. The films obtained were characterized by SEM, x-ray diffraction, optical and electrical measurements. It was found that the sputtering ZnO films were highly orientation growth with the c-axis perpendicular to the substrate surface. The measurements showed that there was a striking seebeck effect in the ZnO films, and their thermoelectric power was linearly increased with increasing temperature. The experimental results were also demonstrated that the thermoelectric power was degraded under the magnetic field. This finding may ascribe to the magneto resistive effect.

La and Co doping effects on magnetoresistance of double perovskite Sr2FeMoO6

2015 ◽  
Vol 29 (20) ◽  
pp. 1550140 ◽  
Author(s):  
SongChol Ri ◽  
GwangSu Kim
Keyword(s):  
Magnetic Field ◽  
Doping Concentration ◽  
Magnetic Measurements ◽  
Double Perovskite ◽  
High Energy ◽  
X Ray Diffraction ◽  
Co Doping ◽  
Maximum Value ◽  
Doping Effects ◽  
Low Magnetic Field

Double perovskite Sr 2 FeMoO 6 (SFMO) with composition of Sr 2-x La x Fe 1-y Co y MoO 6(x = 0, 0.1, 0.2, 0.3, 0.4, 0.5 at.%; y = 0, 0.05, 0.1, 0.2, 0.3, 0.5, 0.9 at.%) was synthesized by high energy ball milling and sintering. The sintered samples were investigated by means of X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and magnetic measurements. XRD results show that all the samples have single phase double perovskite structure. EDS spectrum confirmed that the actual composition of prepared samples is in agreement with nominal ones. With the increase of doping concentration of La, the magnetization decreases, whereas Curie temperature increases in SFMO. And with doping concentration of La, the magnetoresistance (MR) ratio with a low magnetic field of 480 kA/m increases, has its maximum value as 5% for x = 0.3 at 293 K. The degree of antisite disorder decreases with Co 2+ doping, and therefore results in increase of MR ratio. At room temperature, the MR ratio with a considerable low magnetic field for x = 0.3, y = 0.1 has maximum value as 6.5%.

Texture of Gold-Palladium Couples

1997 ◽  
Vol 472 ◽  
Author(s):  
Young S. Chung ◽  
Keenan Evans ◽  
William Glaunsinger
Keyword(s):  
Thin Films ◽  
Silicon Dioxide ◽  
Seed Layer ◽  
Substrate Surface ◽  
Diffusion Mechanism ◽  
Strong Dependence ◽  
Gold Films ◽  
X Ray Diffraction ◽  
Pole Figures ◽  
Polycrystalline Gold

ABSTRACTThe crystal textures of polycrystalline films of gold-palladium couples on an oxidized silicon (100) substrates were investigated via x-ray diffraction (XRD) pole figures. Studies were performed on both as-deposited and thermally annealed films. Scanning electron microscopy (SEM) was used to examine the microstructures of the seed layer thin films as deposited. The {111} texture formation of gold-palladium thin film couples displayed a strong dependence on the nature of the underlying seed layer. Gold films deposited on a palladium seed layer revealed much less degree of {111} texture, than gold films deposited directly on a silicon dioxide surface. In contrast, palladium films deposited on polycrystalline gold films showed a higher degree of {111} texture, compared to palladium films deposited directly on silicon dioxide. The {111} texture of annealed gold-palladium alloy thin films was greater for palladium on gold than for gold on palladium. These results are interpreted in terms of the gold-palladium diffusion mechanism and the interaction of the condensing metals with the oxygens of the SiO2 substrate surface.

Glass-Coated Cu-Mn-Ga Microwires Produced by Taylor-Ulitovsky Technique

2009 ◽  
Vol 152-153 ◽  
pp. 79-84 ◽  
Author(s):  
Joan Josep Suñol ◽  
L. Escoda ◽  
C. García ◽  
V.M. Prida ◽  
Victor Vega ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solid Solution ◽  
Curie Temperature ◽  
Energy Dispersive Spectroscopy ◽  
Room Temperature ◽  
Alloy Composition ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Magnetic Field

Glass-coated Cu-Mn-Ga microwires were fabricated by Taylor-Ulitovsky technique. By means of energy dispersive spectroscopy microanalysis, an average alloy composition of Cu56Ga28Mn16 was determined. The temperature dependence of magnetization measured at a low magnetic field showed the coexistence of two ferromagnetic phases. The Curie temperature of one phase is 125 K and above room temperature for the other one. X-ray diffraction at room temperature and at 100 K reflects the presence of the same three crystalline phases corresponding to the cubic B2 Cu-Mn-Ga structure as a main phase and the minor phases of fcc Cu rich solid solution with Mn and Ga and the monoclinic CuO.

scholarly journals Low Magnetic Field Response in Ferronematics

2017 ◽  
Vol 131 (4) ◽  
pp. 934-936
Author(s):  
V. Gdovinová ◽  
N. Tomašovičová ◽  
V. Závišová ◽  
N. Éber ◽  
T. Tóth-Katona ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Response ◽  
Low Magnetic Field

Effect of Al substitution for Ga on magnetostriction enhancement by annealing of as-cast Fe–Ga–Al alloys under low magnetic fields

2020 ◽  
Vol 111 (4) ◽  
pp. 332-338
Author(s):  
Yan Zhou ◽  
Lifang Zhang ◽  
Dandan Zhao ◽  
Jingyu Gong ◽  
Wei Zhu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Vacuum ◽  
Vacuum Arc ◽  
X Ray Diffraction ◽  
Arc Melting ◽  
Vacuum Arc Melting ◽  
Al Substitution ◽  
Field Annealing ◽  
Magnetostriction Coefficient ◽  
Low Magnetic Field

Abstract Samples of Fe82Ga18-xAlx (1.5 £ x £ 15) alloys were prepared using a high vacuum arc melting system and homogenized at 1100 8C for 3 h, 1 000 8C for 120 h, and 730 8C for 168 h. The Fe82Ga18-xAlx(3 £ x £ 13.5) alloys were annealed at 550 8C for 15 min, while being exposed to a low magnetic field. The structure of the alloys was analysed by X-ray diffraction and optical microscopy. The magnetostriction coefficient of each of the samples was measured. It was found that the magnetostriction values of Fe82Ga18-xAlx(3 £ x £ 13.5) alloys were enhanced by magnetic field annealing. The magnetostrictive growth rate of the Fe82Ga15Al3sample was particularly large at 165%, and the Fe82Ga9Al9sample showed the highest magnetostrictive coefficient (up to 114 · 10-6) without compressive stress.

Fabrication and Properties of Epitaxial Buffer Layers on Nonmagnetic Textured Ni Based Alloy Substrates

1999 ◽  
Vol 13 (09n10) ◽  
pp. 1029-1034 ◽  
Author(s):  
G. Celentano ◽  
V. Boffa ◽  
L. Ciontea ◽  
F. Fabbri ◽  
V. Galluzzi ◽  
...  
Keyword(s):  
Buffer Layer ◽  
Ybco Film ◽  
Lattice Mismatch ◽  
Substrate Surface ◽  
Liquid Nitrogen Temperature ◽  
Metallic Substrate ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
Metallic Substrates ◽  
Layer Deposition

Biaxially aligned YBCO thick films on oxide buffered metallic substrates is a promising route toward the fabrication of superconducting tapes operating at liquid nitrogen temperature. The role of buffer layer is to reduce the lattice mismatch between the substrate and the YBCO film, to adapt the thermal expansion coefficient, to hamper the diffusion of Ni in YBCO film and to prevent the oxidation of the metallic substrate surface. This paper presents a study regarding CeO 2 buffer layer deposition on a new nonmagnetic (001)[100] textured Ni-V alloy substrates. The deposition of CeO 2 was performed by both pulsed laser ablation and e-beam evaporation techniques. The θ-2θ X-ray diffraction pattern mainly exhibits the (00l) peaks of CeO 2, indicating that the films are epitaxially grown with the c axis perpendicular to the substrate. Rocking curved through the CeO 2 (002) peak have a FWHM of about 6°. The SEM studies have shown that the surface is smooth, continuos and free of cracks. Texture analysis reveals a good in-plane orientation for the ablated CeO 2 film, whereas the electron beam evaporated CeO 2 shows two textures in the growth plane. Further efforts are focused on the deposition of YBCO thick film on the as buffered nonmagnetic metallic substrate.

Magnetostriction and Hysteresis of (Tb,Dy,Ho)Fe2 Alloys

2007 ◽  
Vol 546-549 ◽  
pp. 2205-2208 ◽  
Author(s):  
Hong Bo Zhang ◽  
Cheng Bao Jiang
Keyword(s):  
Magnetic Field ◽  
Curie Temperature ◽  
Magnetic Anisotropy ◽  
Lattice Parameter ◽  
Anisotropy Constant ◽  
Spin Reorientation ◽  
X Ray Diffraction ◽  
Diffraction Patterns ◽  
Low Magnetic Field ◽  
Operating Temperature Range

The Tb/Dy ratio of Tb0.30Dy0.70Fe1.95 giant magnetostrictive alloy was shifted away from 0.30/0.70 to 0.36/0.64 to enlarge the operating temperature range. However, the magnetostriction was reduced under low magnetic field and its hysteresis was enlarged with the shift of Tb/Dy ratio. Ho addition improves the magnetostriction under low magnetic field and reduces the hysteresis of TbxDyyHozFe1.95 (x+y+z=1). The crystal structure, lattice constant, Curie temperature, spin reorientation temperature, magnetization, magnetic anisotropy and magnetostriction of TbxDyyHozFe1.95 alloys were investigated. X-ray diffraction patterns demonstrate that all the samples possess MgCu2-type cubic Laves structure. The lattice parameter, Curie temperature and magnetic anisotropy constant K1 decreased with increasing Ho concentration. The hysteresis represented by the width of magnetostriction versus the applied field was reduced due to the addition of Ho. At a compressive stress of 10 MPa and a magnetic field of 1000Oe, the addition of Ho to the ternary TbxDyyFe1.95 compound reduced the width of magnetostriction by 25% for Tb0.296Dy0.472Ho0.232Fe1.95 and by 27% for Tb0.296Dy0.472Ho0.232Fe1.95 compared to the Tb0.36Dy0.64Fe1.95 alloy, while the strains were reduced by only 3% and 9%.

Influence of grain boundaries and voids on the saturated magnetization in Fe/sub 3/O/sub 4/ films at a low magnetic field

2006 ◽  
Vol 42 (5) ◽  
pp. 1495-1498 ◽  
Author(s):  
Ki Woong Kim ◽  
Kap Soo Yoon ◽  
Ja Hyun Koo ◽  
Young Ho Do ◽  
Chae Ok Kim ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Grain Boundaries ◽  
Low Magnetic Field
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