Microstructural and Magnetic Characterization of Ni Films with In-Plane Anisotropy Induced by Ion Bombardment During Growth

1992 ◽  
Vol 268 ◽  
Author(s):  
W. A. Lewis ◽  
H. Saffari ◽  
M. Farle ◽  
E. Kay ◽  
S. B. Hagstrom
Keyword(s):  
Ion Beam ◽  
Flux Ratio ◽  
Magnetic Behavior ◽  
Ion Bombardment ◽  
Angle Of Incidence ◽  
Magnetization Direction ◽  
Direction Parallel ◽  
Plane Anisotropy ◽  
Amorphous Quartz ◽  
Quartz Substrates

ABSTRACTNi films 250 to 1500 Å thick are prepared on polished amorphous quartz substrates in ultrahigh vacuum by ion beam sputter deposition. The growing film is bombarded simultaneously with Xe+ ions at an oblique angle of incidence. The structural and magnetic modifications are studied for different film thicknesses as a function of Xe+ ion energies (50–200 eV) and relative flux of arriving Ni atoms/Xe ions at the substrate. Lattice spacings and degree of texturing are determined by x-ray diffraction. Magnetic in-plane anisotropy is determined by longitudinal magneto-optic Kerr effect measurements. Our results show that an uniaxial in-plane magnetic anisotropy is induced with the hard magnetization direction parallel to the plane of incidence of the secondary Xe+ ions, and a (111) texture with an increased plane spacing of 0.5% is measured. The microstructure of the film and the magnitude of the anisotropy is sensitive to film thickness and flux ratio. For films prepared without secondary ion bombardment, the plane spacings correspond to those for bulk Ni, and isotropic magnetic behavior is observed.

Angle of Incidence Effects in Ion Beam Processing

1988 ◽  
Vol 128 ◽  
Author(s):  
J. M. E. Harper ◽  
S. E. Hörnström ◽  
P. J. Rudeck ◽  
R. M. Bradley
Keyword(s):  
Etch Rate ◽  
Ion Beam ◽  
Etching Rate ◽  
Normal Incidence ◽  
Ion Bombardment ◽  
Angle Of Incidence ◽  
Processing Parameter ◽  
Ion Beam Etching ◽  
Characteristic Wavelength ◽  
Glancing Angle

ABSTRACTThe angle of incidence of ion bombardment is an important processing parameter, which can strongly affect the shape, composition and microstructure of bombarded surfaces. We describe several phenomena directly related to the angle of ion incidence during ion beam etching and ion beam assisted deposition. First, the development of surface ripple topography during ion beam etching is modeled. Surface perturbations are shown to grow under ion bombardment, while surface selfdiffusion acts to select a characteristic wavelength. The orientation of these characteristic ripples changes by 90° as the angle of ion incidence is varied from near-normal to near-glancing angle. The second example is the effect of angle of incidence on the etching rate of Ta under mixed Ar-O2 ion bombardment. For pure Ar bombardment, the sputtering yield of Ta increases with angle of ion incidence slower than secθ, producing a maximum etch rate at normal incidence. Above a critical pressure of O2, however, the yield increases faster than secθ dependence, producing a maximum etch rate at a non-normal angle of incidence. The third example is the effect of angle of incidence on the preferential sputtering of Al relative to Cu in Al-5% Cu thin films. Films deposited by evaporation with simultaneous Ar ion bombardment at 500 eV show a depletion of Al relative to Cu. This composition change is enhanced by increasing the angle of incidence away from normal, resulting in a higher Cu concentration in a film deposited on a tilted surface. Finally, a mechanism is described for the generation of oriented microstructure in films deposited under simultaneous glancing-angle ion bombardment, demonstrated previously for Nb. Grain orientations are selected which allow channelling of the ion beam. These results show that the shape, composition and microstructure of films deposited under ion bombardment respond to changes in angle of incidence, and that these effects need further study and modeling.

Lorentz electron microscopy of magnetic domains in rapidly solidified and annealed Pt-Co-B alloys

1991 ◽  
Vol 49 ◽  
pp. 784-785
Author(s):  
N. Qiu ◽  
J. E. Wittig
Keyword(s):  
Rapid Solidification ◽  
Ion Beam ◽  
Magnetic Behavior ◽  
High Coercivity ◽  
Magnetic Domains ◽  
Beam Angle ◽  
Tem Analysis ◽  
Intrinsic Coercivity ◽  
Hard Magnets ◽  
Rapidly Solidified

PtCo hard magnets have specialized applications owing to their relatively high coercivity combined with corrosion resistance and ductility. Increased intrinsic coercivity has been recently obtained by rapid solidification processing of PtCo alloys containing boron. After rapid solidification by double anvil splat quenching and subsequent annealing for 30 minutes at 650°C, an alloy with composition Pt42Co45B13 (at.%) exhibited intrinsic coercivity up to 14kOe. This represents a significant improvement compared to the average coercivities in conventional binary PtCo alloys of 5 to 8 kOe.Rapidly solidified specimens of Pt42Co45B13 (at.%) were annealed at 650°C and 800°C for 30 minutes. The magnetic behavior was characterized by measuring the coercive force (Hc). Samples for TEM analysis were mechanically thinned to 100 μm, dimpled to about 30 nm, and ion milled to electron transparency in a Gatan Duomill at 5 kV and 1 mA gun current. The incident ion beam angle was set at 15° and the samples were liquid nitrogen cooled during milling. These samples were analyzed with a Philips CM20T TEM/STEM operated at 200 kV.

Ion Beam Mixing of Ni-Ti Bilayered Thin Films

1985 ◽  
Vol 43 ◽  
pp. 290-291
Author(s):  
A. K. Rai ◽  
R. S. Bhattacharya ◽  
M. H. Rashid
Keyword(s):  
Crystal Structure ◽  
Thin Films ◽  
Amorphous Alloys ◽  
Ion Beam ◽  
Ion Bombardment ◽  
High Energy ◽  
Mixing Efficiency ◽  
Ion Beam Mixing ◽  
Enhanced Diffusion ◽  
Binary Metal

Ion beam mixing has recently been found to be an effective method of producing amorphous alloys in the binary metal systems where the two original constituent metals are of different crystal structure. The mechanism of ion beam mixing are not well understood yet. Several mechanisms have been proposed to account for the observed mixing phenomena. The first mechanism is enhanced diffusion due to defects created by the incoming ions. Second is the cascade mixing mechanism for which the kinematicel collisional models exist in the literature. Third mechanism is thermal spikes. In the present work we have studied the mixing efficiency and ion beam induced amorphisation of Ni-Ti system under high energy ion bombardment and the results are compared with collisional models. We have employed plan and x-sectional veiw TEM and RBS techniques in the present work.

scholarly journals Stable Cu2O Photoelectrodes by Reactive Ion Beam Sputter Deposition

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Ching-Hsiu Chen ◽  
Assamen Ayalew Ejigu ◽  
Liang-Chiun Chao
Keyword(s):  
Electrode Materials ◽  
Variable Temperature ◽  
Ion Beam ◽  
Sputter Deposition ◽  
Flow Rates ◽  
Vacancy Defects ◽  
Photoluminescence Study ◽  
P Type ◽  
Quartz Substrates ◽  
Ion Beam Sputter Deposition

Cu2O has been deposited on quartz substrates by reactive ion beam sputter deposition. Experimental results show that by controlling argon/oxygen flow rates, both n-type and p-type Cu2O samples can be achieved. The bandgap of n-type and p-type Cu2O were found to be 2.3 and 2.5 eV, respectively. The variable temperature photoluminescence study shows that the n-type conductivity is due to the presence of oxygen vacancy defects. Both samples show stable photocurrent response that photocurrent change of both samples after 1,000 seconds of operation is less than 5%. Carrier densities were found to be 1.90 × 1018 and 2.24 × 1016 cm−3 for n-type and p-type Cu2O, respectively. Fermi energies have been calculated, and simplified band structures are constructed. Our results show that Cu2O is a plausible candidate for both photoanodic and photocathodic electrode materials in photoelectrochemical application.

Pulsed laser deposition of oriented V2O5 thin films

2000 ◽  
Vol 15 (10) ◽  
pp. 2249-2265 ◽  
Author(s):  
Jeanne M. McGraw ◽  
John D. Perkins ◽  
Falah Hasoon ◽  
Philip A. Parilla ◽  
Chollada Warmsingh ◽  
...  
Keyword(s):  
Thin Films ◽  
Pulsed Laser Deposition ◽  
Oxygen Pressure ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
Glass Substrates ◽  
Wide Range ◽  
Phase Pure ◽  
Amorphous Quartz ◽  
Quartz Substrates

We have found that by varying only the substrate temperature and oxygen pressure five different crystallographic orientations of V2O5 thin films can be grown, ranging from amorphous to highly textured crystalline. Dense, phase-pure V2O5 thin films were grown on SnO2/glass substrates and amorphous quartz substrates by pulsed laser deposition over a wide range of temperatures and oxygen pressures. The films' microstructure, crystallinity, and texturing were characterized by electron microscopy, x-ray diffraction, and Raman spectroscopy. Temperature and oxygen pressure appeared to play more significant roles in the resulting crystallographic texture than did the choice of substrate. A growth map summarizes the results and delineates the temperature and O2 pressure window for growing dense, uniform, phase-pure V2O5 films.

Ion Bombardment Effect on the Hardness of Ti(C,N,O) Films Prepared by Ion Beam Controlled Deposition (IBCD)

1992 ◽  
Vol 279 ◽  
Author(s):  
Chen Youshan ◽  
Sun Yilin ◽  
Zhang Fumin ◽  
Mou Haichuan ◽  
Tao Wei ◽  
...  
Keyword(s):  
Film Formation ◽  
Ion Beam ◽  
Ion Bombardment ◽  
Advanced Technology ◽  
Preferential Growth ◽  
Ion Energy ◽  
Lattice Constants ◽  
Film Hardness ◽  
Pure Compounds ◽  
Controlled Deposition

Ion beam controlled deposition (IBCD) or ion beam assisted deposition (IB AD) of Ti(C,N,O) films has been investigated much in the last decade for both the advantage of this advanced technology and the promising properties of such materials. Ti(C,N,O) films are various solid solutions of interstitial compounds TiC, TiN and TiO of F.C.C structure with lattice constants lying between the values of the pure compounds. Some content of oxygen improves their wear resistance due to the lower fn;e enthalpies of such films in comparison with pure TiC and TiN films [1]. Many so-synthesizcd titanium carbide and titanium nitride films reported in published papers were actually of this sort as they often had more or less oxygen content from residual gas in vacuum. A number of papers were contributed to depict the texture and composition dependence of film on the arrival ratio of assisting ions versus deposited atoms (AR) as well as their mechanical properties [2–6]. However, the film formation mechanism in IBCD isn't quite clear yet, especially for cases with assisting ion energy of several to tens of keV. During a course to synthesize Ti(C,N,O) films by IBCD with the two beam technique, datum were accumulated. Based on a part of it, a previous paper on ion beam governed preferential growth in IBCD has been published [7]. This paper was aimed to search for the origin of ion bombardment effect on film hardness.

Fractal and Non-Fractal Surfaces in Ion Sputtering

1995 ◽  
Vol 407 ◽  
Author(s):  
A.-L. Barabási ◽  
R. Cuerno
Keyword(s):  
Nonlinear Equation ◽  
Penetration Depth ◽  
Experimental Studies ◽  
Ion Bombardment ◽  
Physical Parameters ◽  
Angle Of Incidence ◽  
Ion Sputtering ◽  
Scaling Properties ◽  
Fractal Surfaces ◽  
Experimental Parameters

ABSTRACTRecently a number of experimental studies focusing on the scaling properties of surfaces eroded by ion bombardment provided apparently contradictory results. A number of experiments report the observation of self-affine fractal surfaces, while others provide evidence about the development of a non-fractal periodic ripple structure. To explain these discrepancies, here we derive a stochastic nonlinear equation that describes the evolution and scaling properties of surfaces eroded by ion bombardment. The coefficients appearing in the equation can be calculated explicitly in terms of the physical parameters characterizing the sputtering process. We find that transitions may take place between various scaling behaviors when experimental parameters, such as the angle of incidence of the incoming ions or their average penetration depth, are varied.

scholarly journals Magnetic Structure of Ion-Beam Imprinted Stripe Domains Determined by Neutron Scattering

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 752 ◽  
Author(s):  
Thomas Saerbeck ◽  
Henning Huckfeldt ◽  
Boris P. Toperverg ◽  
Arno Ehresmann
Keyword(s):  
Magnetic Structure ◽  
Layer Structure ◽  
Ion Beam ◽  
Quantitative Description ◽  
Magnetic Layer ◽  
Magnetic Domain ◽  
Quantitative Information ◽  
Magnetic Vector ◽  
Stripe Domain ◽  
Magnetization Direction

We present a detailed analysis of the in-plane magnetic vector configuration in head-to-head/tail-to-tail stripe domain patterns of nominal 5 μm width. The patterns have been created by He-ion bombardment induced magnetic patterning of a CoFe/IrMn3 exchange bias thin-film system. Quantitative information about the chemical and magnetic structure is obtained from polarized neutron reflectometry (PNR) and off-specular scattering (OSS). The technique provides information on the magnetic vector orientation and magnitude along the lateral coordinate of the sample, as well as the chemical and magnetic layer structure as a function of depth. Additional sensitivity to magnetic features is obtained through a neutron wave field resonance, which is fully accounted for in the presented analysis. The scattering reveals a domain width imbalance of 5.3 to 3.7 μm of virgin and bombarded stripes, respectively. Further, we report that the magnetization in the bombarded stripe significantly deviates from the head-to-head arrangement. A domain wall of 0.6 μm with homogeneous magnetization direction is found to separate the two neighboring domains. The results contain detailed information on length scales and magnetization vectors provided by PNR and OSS in absolute units. We illustrate the complementarity of the technique to microscopy techniques for obtaining a quantitative description of imprinted magnetic domain patterns and illustrate its applicability to different sample systems.

Ion Beam Processing of Optical Thin Films

1989 ◽  
Vol 152 ◽  
Author(s):  
U. J. Gibson
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Ion Beam ◽  
Ion Bombardment ◽  
Sensitive Function ◽  
Deposition Conditions

ABSTRACTThe microstructure and optical properties of vacuum evaporated coatings are a sensitive function of the deposition conditions. In recent years, ion bombardment has been used increasingly for the production of denser, more stable coatings of oxides and other materials. In addition to modifying the microstructure, ion bombardment is emerging as a valuable tool for altering the composition (and hence the optical properties) of thin films. A discussion of the effects of ion beam processing and the methods used to analyze the changes in these films is presented.

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