In-plane Anisotropy in Hetero-Amorphous (CoFeB)-SiO2 Thin Films

2002 ◽  
Vol 754 ◽  
Author(s):  
P. Johnsson ◽  
I. Aoqui ◽  
K. Nötzold ◽  
J. Allebert ◽  
M. Munakata ◽  
...  
Keyword(s):  
Thin Films ◽  
Giant Magnetoresistance ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Rf Magnetron Sputtering ◽  
Film Plane ◽  
Amorphous Thin Films ◽  
Plane Anisotropy ◽  
Hopping Model ◽  
Variable Range Hopping Model

ABSTRACTIn order to engineer materials suitable for micromagnetic inductor cores we have fabricated and investigated the properties of granular (CoFeB)-SiO2 amorphous thin films. The deposition method, synchronous triple-rf magnetron sputtering onto rotating substrates, induces anisotropy in the film plane. Here we present magnetic hysteresis loops, resistivity and magnetoresistance measurements of two of these films, with different amount of metallic content. Both films have anisotropic resistivity, which is higher for the film with less metallic content. The low-metallic-content film exhibits typical isotropic giant magnetoresistance (GMR), while the film with higher metallic content shows a mixture of GMR and anisotropic magnetoresistance (AMR). The AMR appears at fields below 500 Oe. We believe that this has not been observed before in amorphous samples. The behaviour of the resistivity versus temperature ρ (T) indicates that the sample with lower metallic content consists of isolated grains while the high-metallic-content sample consists of a percolated network. Experimental ρ (T) data for the low-metallic-content sample fit: to the variable-range hopping model at temperatures lower than 221 K and can be described by excitation of the carriers to the mobility edge at higher temperatures.

Giant Magnetoresistance in As-Sputter-Deposited Au/NiFe Multilayer Thin Films

1994 ◽  
Vol 343 ◽  
Author(s):  
W. Y. Lee ◽  
G. Gorman ◽  
R. Savoy
Keyword(s):  
Thin Films ◽  
Exchange Coupling ◽  
Giant Magnetoresistance ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Multilayer Films ◽  
Antiferromagnetic Coupling ◽  
Multilayer Thin Films ◽  
Glass Substrates ◽  
Sputter Deposited

ABSTRACTGiant magnetoresistance with low saturation fields (Hs’s) is reported in Au and permalloy (Ni0.82Fe0.18) or Co-doped permalloy multilayer thin films as-deposited on Ta-overcoated Si and glass substrates. A ΔR/R as high as 4.0% with ≈25 Oe Hs was observed at 295 K for the film consisting of 10 layers of 24 Å Au/13 Å Ni0.82Fe0.18 deposited on a 3 Å Ta-overcoated glass at 50 °C. A Hs value as low as ≈20 Oe with a 15% smaller ΔR/R has been observed for the films with a thicker (e.g., 50 Å) Ta underlayer. Magnetic hysteresis loops of these films indicate the presence of antiferromagnetic exchange coupling between the Ni0.82Fe0.18 layers. This exchange coupling is much smaller for the multilayer films without the Ta underlayer, resulting in a 6x smaller ΔR/R and lOx larger Hs observed for these films. Results of x-ray diffraction analysis indicate stronger (111) texturing for the multilayer films with a Ta underlayer, consistent with the stronger antiferromagnetic coupling between the the Ni0.82Fe0.18 layers in the film. The addition of 2–10 % Co moderately increases the ΔR/R value, but also increases substantially the Hs (up to ≈200 Oe).

Ferroelectric Property and Microstructures of La-Doped Bi4Ti3O12 Thin Films

2013 ◽  
Vol 537 ◽  
pp. 114-117
Author(s):  
X.A. Mei ◽  
Rui Fang Liu ◽  
C.Q. Huang ◽  
J. Liu
Keyword(s):  
Thin Films ◽  
Hysteresis Loops ◽  
Differential Resistance ◽  
Rf Magnetron Sputtering ◽  
Layered Perovskite ◽  
Random Orientation ◽  
Si Substrates ◽  
Current Voltage ◽  
Current Voltage Characteristics ◽  
La Doped

La-doped bismuth titanate (Bi4-xLaxTi3O12: BLT) and pure Bi4Ti3O12 (BIT) thin films with random orientation were fabricated on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering technique. These samples had polycrystalline Bi-layered perovskite structure without preferred orientation, and consisted of well developed rod-like grains with random orientation. For the samples with x=0.25 and 1.0 the current-voltage characteristics exhibited negative differential resistance behaviors and their P-V hysteresis loops were characterized by large leakage current, whereas for the samples with x=0.5 and 0.75 the current-voltage characteristics showed simple ohmic behaviors and their P-V hysteresis loops were the saturated and undistorted hysteresis loops. The remanent polarization ( Pr ) and coercive field (Ec) of the BLT ceramic with x=0.75 were above 20μC/cm2 and 85KV/cm , respectively.

scholarly journals Iron-Doped Lithium Tantalate Thin Films Deposited by Magnetron Sputtering: A Study of the Iron Role in the Structure and the Derived Magnetic Properties

Crystals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 50 ◽  
Author(s):  
Sergio David Villalobos Mendoza ◽  
José Trinidad Holguín Momaca ◽  
José Trinidad Elizalde Galindo ◽  
Diana María Carrillo Flores ◽  
Sion Federico Olive Méndez ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Blocking Temperature ◽  
Ferromagnetic Behavior ◽  
Zero Field ◽  
Cooling Curves ◽  
X Ray Diffraction ◽  
Field Cooling

Fe-doped LiTaO3 thin films with a low and high Fe concentration (labeled as LTO:Fe-LC and LTO:Fe-HC, respectively) were deposited by magnetron sputtering from two home-made targets. The dopant directly influenced the crystalline structure of the LiTaO3 thin films, causing the contraction of the unit cell, which was related to the incorporation of Fe3+ ions into the LiTaO3 structure, which occupied Li positions. This substitution was corroborated by Raman spectroscopy, where the bands associated with Li-O bonds broadened in the spectra of the samples. Magnetic hysteresis loops, zero-field cooling curves, and field cooling curves were obtained in a vibrating sample magnetometer. The LTO:Fe-HC sample demonstrates superparamagnetic behavior with a blocking temperature of 100 K, mainly associated with the appearance of Fe clusters in the thin film. On the other hand, a room temperature ferromagnetic behavior was found in the LTO:Fe-LC layer where saturation magnetization (3.80 kAm−1) and magnetic coercivities were not temperature-dependent. Moreover, the crystallinity and morphology of the samples were evaluated by X-ray diffraction and scanning electron microscopy, respectively.

GMR, Structural, and Magnetic Studies in NiFeCo/Ag Multilayer thin Films

1994 ◽  
Vol 343 ◽  
Author(s):  
J.D. Jarratt ◽  
J.A. Barnard
Keyword(s):  
Giant Magnetoresistance ◽  
Uniaxial Anisotropy ◽  
Hysteresis Loops ◽  
Film Plane ◽  
Film Structure ◽  
X Ray Diffraction ◽  
Magnetic Studies ◽  
Lower Temperature ◽  
Deposited Films

ABSTRACTGiant Magnetoresistance (GMR), crystal structure, and magnetic properties have been investigated in a series of sputtered Ni66Fe16Co18/Ag multilayer films with induced uniaxial anisotropy. The film thickness ranges studied were 20 and 25 Å for NiFeCo, and 25 to 50 Å for Ag. GMR was only evident in the films after post-deposition annealing. This onset of GMR is thought to be due to the breaking up of the NiFeCo layers into ferromagnetic platelets or islands by the immiscible Ag diffusing perpendicular to the film plane along the grain boundaries. The magnitude and field sensitivity of the GMR was dependent on the annealing time and temperature. High angle x-ray diffraction (HXRD) was used to reveal the overall film structure and growth texture and low angle XRD (LXRD) was used to investigate the quality of the multilayer structures. M-H hysteresis loops revealed in-plane uniaxial anisotropy in as-deposited films which is eventually eliminated with annealing. The easy axis squareness experiences a pronounced decrease with lower temperature annealing, but then increases slightly with annealing temperature.

Ferroelectricity, ferromagnetism, and magnetoelectric coupling in highly textured thin films of the multiferroic Pb(Fe0.5Nb0.5)O3

2012 ◽  
Vol 1454 ◽  
pp. 51-56 ◽  
Author(s):  
Oscar Raymond-Herrera ◽  
Paola Góngora-Lugo ◽  
Carlos Ostos ◽  
Mario Curiel-Alvarez ◽  
Dario Bueno-Baques ◽  
...  
Keyword(s):  
Thin Films ◽  
Hysteresis Loops ◽  
Rf Magnetron Sputtering ◽  
Magnetoelectric Coupling ◽  
Ferroelectric Materials ◽  
Zero Field ◽  
Different Temperatures ◽  
Ferroelectric Hysteresis ◽  
First Time ◽  
Magnetization Behavior

ABSTRACTA study of the ferroelectric and magnetic properties and of the magnetoelectric coupling effects of Pb(Fe0.5Nb0.5)O3 (PFN) thin films, grown on SrRuO3/Si [(100) or (111)] substrates by the rf-magnetron sputtering technique, is presented. Structural, morphological, and compositional characterization was realized using the XRD, AFM, XPS, and TEM techniques. Highly textured single phase films with different thickness (from 45 to 270 nm) were successfully grown without Fe2+ presence. A vertically [110] oriented grainy structure was observed. Polarization vs. electric field (P-E) hysteresis loops exhibit excellent and almost constant values of the maximum (∼ 60 μC/cm2) and remanent (∼ 22 μC/cm2) polarizations in the temperature range from 4 K to room temperature; small values of the coercive field, characteristic of soft ferroelectric materials, are observed in these samples. Measurements of the zero-field cooled (ZFC) and field cooled (FC) magnetization behavior and magnetic (M-H) hysteresis loops were realized at different temperatures between 5 and 300 K. Proof of the existence of ferromagnetic order in the low temperature region (below to 50 K) is discussed and reported for the first time. Values of the maximum (∼ 3 emu/g) and remanent (∼ 1.5 emu/g) magnetizations were obtained. dc magnetic field dependence of the ferroelectric hysteresis loops are shown as evidence of the magnetoelectric coupling.

Electrical Characteristics and Microstructures of Eu2O3-Doped Bi4Ti3O12 Thin Films

2010 ◽  
Vol 177 ◽  
pp. 197-200
Author(s):  
X.A. Mei ◽  
Min Chen ◽  
K.L. Su ◽  
A.H. Cai ◽  
J. Liu ◽  
...  
Keyword(s):  
Thin Films ◽  
Remanent Polarization ◽  
Single Phase ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
Differential Resistance ◽  
Rf Magnetron Sputtering ◽  
Electrical Characteristics ◽  
Si Substrates ◽  
Ferroelectric Hysteresis

Eu2O3-doped bismuth titanate (Bi1-xEuxTi3O12: BET) thin films with random oriention were fabricated on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering technique, and the structures and ferroelectric properties of the films were investigated. XRD studies indicated that all of BET films consisted of single phase of a bismuth-layered structure with well-developed rod-like grains. For samples with x=0.0 , 0.25, 1.0 and 1.25, I-E characteristics exhibited negative differential resistance behaviors and their ferroelectric hysteresis loops were characterized by large leakage current, whereas for samples with x=0.5 and 0.75, I-E characteristics were simple ohmic behaviors and their ferroelectric hysteresis loops were the saturated and undistorted hysteresis loops. The remanent polarization (Pr) and coercive field (Ec) of the BET Film with x=0.75 were above 30μC/cm2 and 85KV/cm , respectively.

Ferroelectric Properties and Microstructures of Pr6O11-Doped Bi4Ti3O12 Thin Films

2010 ◽  
Vol 434-435 ◽  
pp. 281-284
Author(s):  
Min Chen ◽  
A.H. Cai ◽  
X.A. Mei ◽  
K.L. Su ◽  
Chong Qing Huang ◽  
...  
Keyword(s):  
Thin Films ◽  
Remanent Polarization ◽  
Single Phase ◽  
Bismuth Titanate ◽  
Ferroelectric Properties ◽  
Hysteresis Loops ◽  
Rf Magnetron Sputtering ◽  
Si Substrates ◽  
Large Leakage Current ◽  
Ferroelectric Hysteresis

Pr6O11-doped bismuth titanate (BixPryTi3O12: BPT) thin films with random oriention were fabricated on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering technique, and the structures and ferroelectric properties of the films were investigated. XRD studies indicated that all of BPT films consisted of single phase of a bismuth-layered structure with well-developed rod-like grains. For samples with y=0.06, 0.3, 1.2 and 1.5, ferroelectric hysteresis loops were characterized by large leakage current, whereas for samples with y=0.6 and 0.9, ferroelectric hysteresis loops were the saturated and undistorted hysteresis loops. The remanent polarization ( Pr ) and coercive field (Ec) of the BPT Film with y=0.9 were above 35μC/cm2 and 80KV/cm , respectively. After 3×1010 switching cycles, 20% degradation of 2Pr is observed in the film with y=0.9.

Preparation and magnetic properties for FeSex/Bi2Se3 bilayer films on silicon substrates by RF magnetron sputtering

2019 ◽  
Vol 12 (02) ◽  
pp. 1950018 ◽  
Author(s):  
J. Zhang ◽  
K. Zhao ◽  
X. S. Yang ◽  
Y. Zhao
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Magnetic Property ◽  
Low Temperature ◽  
Magnetron Sputtering ◽  
Rf Magnetron Sputtering ◽  
Weak Ferromagnetism ◽  
Film Plane ◽  
Silicon Substrates ◽  
Bilayer Films

FeSex/Bi2Se3 bilayer thin films were grown by RF magnetron sputtering on silicon substrates with different thicknesses of Bi2Se3 and the structural, morphological and magnetic properties were investigated. FeSex/Bi2Se3 bilayer films had Bi2Se3 crystallites oriented with c-axis perpendicular to the film plane, and exhibited weak ferromagnetism at low temperature due to the ferromagnetic FeSe2. The thickness of Bi2Se3 layer affected both crystalline structure of Fe–Se layer and the magnetic property.

Influence of Annealing on the Surface Topography and Magnetic Properties of Thin Films of the FINEMET-Type Alloy

2015 ◽  
Vol 233-234 ◽  
pp. 699-704 ◽  
Author(s):  
Evgeniya Mikhalitsyna ◽  
Vasiliy Kataev ◽  
Pavel Geydt ◽  
Vladimir Lepalovsky ◽  
Erkki Lähderanta
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Scanning Probe Microscopy ◽  
Annealing Temperature ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Scanning Probe ◽  
Type Alloy ◽  
Treatment Conditions ◽  
Magnetic Hysteresis Loops

Surface structure and magnetic properties of thin films of the FINEMET-type alloy modificated by Mo (FeCuNbSiBMo) were studied in the aim of establishing of their dependence on heat treatment conditions. The thicknesses of the films were varied from 10 to 800 nm. Dependence of the microstructure of the films surface on the annealing temperature was analyzed using scanning probe microscopy. Parameters of the topography features were estimated as a function of the films thickness and annealing temperature. Magnetic hysteresis loops were measured using vibrating sample magnetometer and discussed in the focus of surface and thickness influences.

Effect of Rapid Thermal Annealing on the Structural and Magnetic Properties of Nanostructured FePt Thin Films

2013 ◽  
Vol 829 ◽  
pp. 396-400
Author(s):  
Younes Jalalizadeh ◽  
Ali Ghasemi ◽  
Gholam Reza Gordani
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Hysteresis Loops ◽  
Rf Magnetron Sputtering ◽  
Phase Identification ◽  
Glass Substrates ◽  
Structural And Magnetic Properties ◽  
Fept Thin Films

The main goal of this study is to investigate the structural and magnetic properties of FePt thin film with respect to the annealing tempreture. The FePt thin films were deposited by RF magnetron sputtering on Corning glass substrates at a room temperature. The films were then post-annealed at the Range of 575-675°C for 20 s by rapid thermal annealing (RTA) at a high heating ramp rate of 100 °Cs. Phase identification of thin films was performed using X-ray diffraction (XRD). With employing SEM, the size and uniformity of grains were studied. Moreover magnetic properties of annealed thin films were evaluated using a vibrating sample magnetometer (VSM). XRD results showed that the ordered FePt structure is formed at 625°C. According to the hysteresis loops, maximum out-of-plane and in-plane coercivity reached 7kOe. this value was achieve at 675°C .These results reveal its significant potential as magnetic recording media for high-density recording.

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