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.

Epitaxial Growth OF (001)- and (111)-Oriented PTMNSB Films and Multilayers

1995 ◽  
Vol 384 ◽  
Author(s):  
M.C. Kautzky ◽  
B.M. Clemens
Keyword(s):  
Kerr Effect ◽  
Single Phase ◽  
Single Layer ◽  
Film Structure ◽  
Interference Effects ◽  
X Ray Diffraction ◽  
Orientation Relationships ◽  
Rocking Curve ◽  
Large Rotations

ABSTRACTIn this paper we report the successful growth of single-phase epitaxial PtMnSb films and multilayers by dc magnetron cosputtering, both in the (001) orientation on MgO(001) and W(001), and in the (111) orientation on Al2O3 (0001). Single-layer films in the thickness range 50Å≤t≤1000Å were grown and characterized using x-ray diffraction (XRD), magneto-optic Kerr effect (MOKE), and vibrating sample magnetometry (VSM). The in-plane orientation relationships, as determined by asymmetric XRD, were PtMnSb[100]∥MgO[110], PtMnSb[100]∥W[100], and PtMnSb[101∥Al2O3[2110]. The crystalline quality of the films was found to depend strongly upon the substrate, growth temperature, film thickness, and presence of a capping layer, but rocking curve widths of 1° or less were achieved on each substrate. Measurement of the in-plane strain showed that the films were almost entirely relaxed, with strains <1%. In-plane magnetization was observed in all cases, with moments and coercivities in the 400-500 emu/cm3 and 100-200 Oe ranges respectively. Polar Kerr spectra showed large rotations (0.75° - 1.03°), whose peak wavelengths appear to depend on both film structure and optical interference effects.

Epitaxial Growth of Strontium Bismuth Tantalate/Niobate on Buffered Magnesium Oxide Substrates

2005 ◽  
Vol 902 ◽  
Author(s):  
George H. Thomas ◽  
Jonathan S. Morrell ◽  
Tolga Aytug ◽  
Ziling B. Xue ◽  
David B. Beach
Keyword(s):  
Buffer Layer ◽  
Magnesium Oxide ◽  
Film Structure ◽  
X Ray Diffraction ◽  
Strontium Bismuth Tantalate ◽  
Solution Deposition ◽  
Oxide Substrates ◽  
Diffraction Patterns ◽  
Deposited Films ◽  
Deposition Techniques

AbstractEpitaxial films of strontium bismuth tantalate (SrBi2Ta2O9, SBT) and strontium bismuth niobate (SrBi2Nb2O9, SBN) were grown using solution deposition techniques on magnesium oxide (MgO) substrates buffered with a 100 nm layer of lanthanum manganate (LaMnO3, LMO). Film structure and texture analyses were carried out using x-ray diffraction. Theta-2theta diffraction patterns were consistent with a c-axis aligned structure for both the buffer layer and the solution deposited films. Theta-2 theta scans revealed (001)SBT, SBN //(001) LMO epitaxial relationships between the solution deposited films and the buffer layer. A pole figure about the SBT, SBN (115) reflection indicated a single in-plane epitaxy. Film quality was assessed using ω and φ scans. Nuclear Magnetic Resonance (13C) was used to characterized the methoxy-ethoxide solutions used for the deposition of the SBN and SBT films.

DEPOSITION AND CHARACTERIZATION OF MAGNETRON CO-SPUTTERED InAlN FILM AT DIFFERENT Ar:N2 GAS FLOW RATIOS

2017 ◽  
Vol 24 (03) ◽  
pp. 1750027 ◽  
Author(s):  
NAVEED AFZAL ◽  
MUTHARASU DEVARAJAN ◽  
KAMARULAZIZI IBRAHIM
Keyword(s):  
Gas Flow ◽  
X Ray Diffraction ◽  
Electrical And Optical Properties ◽  
Text Type ◽  
Increasing Trend ◽  
Analysis Of Results ◽  
Deposited Films ◽  
Gas Ratio

This work presents the influence of changing Ar:N2 gas ratio on the growth and properties of InAlN films. InAlN films were deposited on [Formula: see text]-type Si(111) substrates by using magnetron co-sputtering method in 6:12, 10:10, 12:8 and 12:6 Ar:N2 mixtures at 300[Formula: see text]C. The surface, structural, electrical and optical properties of the deposited films were evaluated at different Ar:N2 ratios. The grain size and film thickness were increased by increasing the Ar flow with respect to N2. Structural characterization by X-ray diffraction (XRD) revealed an improvement in the crystalline quality of the [Formula: see text]-axis-oriented InAlN film by adjusting the Ar:N2 ratio to 12:8, however no diffraction peak corresponding to InAlN was detected at 6:12 Ar:N2 mixture. The surface roughness of InAlN film exhibited an increasing trend whereas the electrical resistivity of the film was decreased by increasing the Ar:N2 ratio. The bandgap of InAlN film was calculated from the optical reflectance spectra and it was found to change by changing the Ar:N2 gas ratio. The analysis of results from this work shows that the InAlN film with improved physical properties can be obtained through reactive magnetron co-sputtering method by adjusting the Ar:N2mixture to 12:8.

Magnetic Force Microscopy on Co/Pt Multilayers

2009 ◽  
Vol 152-153 ◽  
pp. 241-244
Author(s):  
V. Karoutsos ◽  
Panagiotis Poulopoulos ◽  
M. Angelakeris ◽  
E.T. Papaioannou ◽  
Paul Fumagalli ◽  
...  
Keyword(s):  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Magnetic Domain ◽  
Hysteresis Loops ◽  
Electron Beam Evaporation ◽  
Film Plane ◽  
X Ray Diffraction ◽  
Saturation Field ◽  
Force Microscopy ◽  
Magneto Optic

Co/Pt multilayers reside among the best candidates for perpendicular magneto-optic recording. In this work, Co/Pt multilayers were prepared by electron-beam evaporation under ultrahigh vacuum conditions on polyimide. X-ray diffraction measurements revealed the high quality of multilayer stacking. Magneto-optic polar Kerr effect experiments were used in order to obtain magnetization hysteresis loops of the films. We have studied the magnetic-domain morphology on the surface of the films via Magnetic Force Microscopy. The field applied during these measurements was 2.3 kOe oriented perpendicular to the film plane; this field seems to stabilize and enhance out-of-plain stripe domains against in plain domains that may be expected from magnetization curves. Finally, we observed that when the applied field approaches the magnetic saturation field, then the domain morphology turns to be dominated by bubble domains.

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.

scholarly journals Strain-Dependence of the Structure and Ferroic Properties of Epitaxial NiTiO3Thin Films Grown on Different Substrates

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Tamas Varga ◽  
Timothy C. Droubay ◽  
Mark E. Bowden ◽  
Libor Kovarik ◽  
Dehong Hu ◽  
...  
Keyword(s):  
Marked Effect ◽  
Physical Property ◽  
Structural Data ◽  
Weak Ferromagnetism ◽  
Film Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Substrate Choice ◽  
Ferroic Properties

Polarization-induced weak ferromagnetism has been predicted a few years back in perovskite MTiO3(M = Fe, Mn, and Ni). We set out to stabilize this metastable perovskite structure by growing NiTiO3epitaxially on different substrates and to investigate the dependence of polar and magnetic properties on strain. Epitaxial NiTiO3films were deposited on Al2O3, Fe2O3, and LiNbO3substrates by pulsed laser deposition and characterized using several techniques. The effect of substrate choice on lattice strain, film structure, and physical properties was investigated. Our structural data from X-ray diffraction and electron microscopy shows that substrate-induced strain has a marked effect on the structure and crystalline quality of the films. Physical property measurements reveal a dependence of the weak ferromagnetism and lattice polarization on strain and highlight our ability to control the ferroic properties in NiTiO3thin films by the choice of substrate. Our results are also consistent with the theoretical prediction that the ferromagnetism in acentric NiTiO3is polarization induced. From the substrates studied here, the perovskite substrate LiNbO3proved to be the most promising one for strong multiferroism.

scholarly journals Microstructure and Optical Characterization of Mid-Wave HgCdTe grown by MBE under Different Conditions

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 296
Author(s):  
Xiao-fang Qiu ◽  
Sheng-xi Zhang ◽  
Jian Zhang ◽  
Yi-cheng Zhu ◽  
Cheng Dou ◽  
...  
Keyword(s):  
Optical Properties ◽  
Growth Temperature ◽  
Crystal Quality ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Different Temperatures ◽  
Higher Temperature ◽  
Lower Temperature

The mid-wave single-crystal HgCdTe (211) films were successfully grown on GaAs (211) B substrates by molecular beam epitaxy (MBE). Microstructure and optical properties of the MBE growth HgCdTe films grown at different temperatures were characterized by X-ray diffraction, scanning transmission electron microscopy, Raman and photoluminescence. The effects of growth temperature on the crystal quality of HgCdTe/CdTe have been studied in detail. The HgCdTe film grown at the lower temperature of 151 °C has high crystal quality, the interface is flat and there are no micro twins. While the crystal quality of the HgCdTe grown at higher temperature of 155 °C is poor, and there are defects and micro twins at the HgCdTe/CdTe interface. The research results demonstrate that the growth temperature significantly affects the crystal quality and optical properties of HgCdTe films.

Effect of Mn Doping on the Structural and Ferroelectric properties of SrBi2Ta2O9

2004 ◽  
Vol 848 ◽  
Author(s):  
T. Sookawee ◽  
L. Pdungsap ◽  
P. Winotai ◽  
R. Suryanarayanan ◽  
V.M. Naik ◽  
...  
Keyword(s):  
Raman Spectra ◽  
Layer Structure ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
Hysteresis Loops ◽  
Structural Quality ◽  
X Ray Diffraction ◽  
Mn Doping ◽  
Gel Technique

ABSTRACTSrBi2Ta2O9 (SBT) samples have been prepared by sol-gel technique with varying amount of excess Bi added to the starting composition. The excess Bi profoundly affects the dielectric and ferroelectric properties. The dielectric constant (ε) and remnant polarization increases from 80 and 1.4 μ C/cm2 for SBT with 1 mole % of excess Bi to 120 and 6.5 μ C/cm2 for SBT with 20 mole % of excess Bi. The Raman spectra, scanning electron microscopy images and the x-ray diffraction analysis show an improvement in structural quality of the samples with addition of excess Bi to the starting composition. The effect of Mn doping has also been studied by preparing SrBi2Ta2-x Mnx O9 (SBT-Mn) with x = 0 – 0.1. In the case of SBT-Mn samples, the XRD spectra revealed an unknown phase when x > 0.025. However, Raman spectra reveal the retention of Bi layer structure for all Mn compositions, with possibly small distortions. With Mn addition, ε increased to ∼ 140 for x < 0.005, but decreased to ≤ 120 when x > 0.015. The value of ε is independent of frequency from 60 to 85 kHz for all compositions of Mn. The effect of Mn addition resulted in a strong decrease in the area of the hysteresis loops.

Stress in Giant Magnetoresistive Ni66Fe16Co18/Ag Multilayer thin Films

1994 ◽  
Vol 356 ◽  
Author(s):  
J.D. Jarratt ◽  
J.A. Barnard
Keyword(s):  
Thin Films ◽  
Compressive Stress ◽  
Giant Magnetoresistance ◽  
Uniaxial Anisotropy ◽  
Structural Evolution ◽  
Film Plane ◽  
Film Stress ◽  
Bilayer Film ◽  
Multilayer Thin Films ◽  
Thin Film Stress

AbstractThin film stress has been measured in (Ni66Fe16Co18 25 Å/Ag 50 Å) multilayer thin films that exhibit annealing-induced giant magnetoresistance (GMR) known as ‘discontinuous’ GMR1. This GMR results when NiFeCo layers are broken up into discontinuous ferromagnetic islands or platelets by immiscible Ag atom grain boundary diffusion normal to the film plane. As-deposited films display no GMR and are in compression. An MR value of 5 % with a relatively sharp profile can be induced in a ten bilayer sample annealed at 400°C for 15 min. Annealing generally results in a decrease in the as-deposited compressive stress and can result in tensile stress at high enough temperatures. Interestingly, at the annealing temperatures corresponding to the maximum induced GMR, there is a plateau in the otherwise monotonic decrease in compressive stress with increasing temperature.Stress-temperature plots reveal a plateau in the stress value during the heating of a ten bilayer sample due to plastic deformation in the film via densification. Isothermal stress-time plots done on a single sample show increasing compressive stress relief after each successively higher temperature anneal. The stress was also measured in a single bilayer film with the same volume of film as in a ten bilayer sample but far fewer interfaces. High and low angle x-ray diffraction (HXRD, LXRD) was used to reveal the structural evolution with annealing. Magnetic (M-H) hysteresis measurements revealed increasing coercivity and decreasing induced as-deposited in-plane magnetic uniaxial anisotropy with annealing temperature.

Structural and Magnetic Characterization of Bi-Substituted Garnet on Si and GaAs

1995 ◽  
Vol 384 ◽  
Author(s):  
Ken M. Ring ◽  
A.L. Shapiro ◽  
F. Deng ◽  
R.S. Goldman ◽  
F. Spada ◽  
...  
Keyword(s):  
Hysteresis Loops ◽  
Film Structure ◽  
X Ray Diffraction ◽  
Plan View ◽  
Transmission Electron ◽  
Potential Applications ◽  
Novel Material ◽  
Sputter Deposited ◽  
20 Nm

ABSTRACTNovel material structures that combine magneto-optic (MO) and semiconductor devices have potential applications in monolithic microwave systems and optoelectronics. We have investigated the materials issues pertaining to the film structure, interface uniformity, and magnetic/MO properties of (BiDy)3(FeGa)5O12 (Bi-DyIG) thin films sputter deposited on Si and GaAs. The rapid thermally annealed films were polycrystalline with a nominal grain size of 20 nm. The magnetic and MO properties were strongly dependent on the type of substrate such that square hysteresis loops and coercivities of 0.1 to 0.9 kOe were observed for Bi-DyIG/Si structures while Bi-DyIG/GaAs structures showed much lower coercivity values (0.03 kOe). A comparison of the magnetic properties, microstructure and substrate composition was carried out with plan-view and cross-section transmission electron microscopy, as well as electron and x-ray diffraction. The results suggest that grain orientation effects, stress, and compositional inhomogeneity due to interfacial reactions or diffusion introduced by the substrate strongly influence the magnetic and MO properties of the films.

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