Ion-Implantation/Annealing-Induced Precipitation of Nanophase Ferromagnetic Particles In Yttrium-Stabilized ZrO2

1998 ◽  
Vol 540 ◽  
Author(s):  
S. Honda ◽  
F.A. Modine ◽  
A. Meldrum ◽  
J.D. Budai ◽  
T.E. Haynes ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Magnetic Circular Dichroism ◽  
Critical Factor ◽  
Surface Region ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Near Surface ◽  
Annealing Conditions ◽  
Optical Effects ◽  
Processing Techniques

AbstractIon implantation and thermal processing techniques have been used to form embedded ferromagnetic nanophase precipitates and thereby create magneto-optically active near-surface regions on otherwise inactive materials. Ferromagnetic precipitates were formed by first implanting Fe+ or Ni− into Y0.15Zr0.85O1.93(YSZ) with an implant energy of 140 keV, a fluence of 8.0 × 1016 ions/cm2, and at a temperature of-189°C. After implantation, the specimens were annealed at temperatures ranging from 500 to 1100°C in several types of reducing atmospheres. X-ray diffraction and TEM analysis of the Fe- or Ni-implanted/annealed specimens revealed that crystallographically coherent precipitates of metallic α-Fe, magnetite (Fe3O4), or Ni could be formed in YSZ depending on the annealing conditions. In particular, the cooling rate was established as the critical factor that determined whether Fe or Fe3O4 precipitates were created. Magneto-optical effects arising from ferromagnetic precipitates of Fe, Fe3O4, and Ni in the near-surface region of YSZ were observed and characterized using magnetic circular dichroism (MCD). The magneto-optical response of the α-Fe, Fe3O4, and Ni precipitates was markedly different as indicated by the MCD-detected hysteresis curves. The precipitation mechanism, the chemical nature of the precipitates, and the particle-size distributions resulting from different annealing conditions were investigated and correlated with the precipitate magneto-optical properties.

The Formation of High-Coercivity, Oriented, Nanophase Cobalt Precipitates in Al2O3 Single Crystals by Ion Implantation

1999 ◽  
Vol 581 ◽  
Author(s):  
S. Honda ◽  
F. A. Modine ◽  
T. E. Haynes ◽  
A. Meldrum ◽  
J. D. Budai ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Ion Implantation ◽  
Single Crystals ◽  
Data Storage ◽  
Magnetic Circular Dichroism ◽  
Surface Region ◽  
Magnetic Data ◽  
High Coercivity ◽  
Saturation Field ◽  
Near Surface

ABSTRACTIon-implantation and thermal-processing methods have been used to form nanophase magnetic precipitates of metallic cobalt that are embedded in the near-surface region of single crystals of Al2O3. The Co precipitates are isolated, single-crystal particles that are crystallographically oriented with respect to the host Al2O3 lattice. Embedded nanophase Co precipitates were formed by the implantation of Co+ at an energy of 140 keV and a dose of 8 × 1016 ions/cm2 followed by annealing in a reducing atmosphere. The implanted/annealed Co depth profile, particle size distributions and shapes, and the orientational relationship between the nanophase precipitates and the host crystal lattice were determined using RBS/channeling, transmission electron microscopy, and x-ray diffraction. Magneto-optical effects arising from Co precipitates formed in the near-surface region of Al2O3 were observed and characterized using magnetic circular dichroism. Magnetic properties of the Co-particle/host nanocomposites were investigated in the temperature range of 77 to 295 K in applied fields of up to 10 kG using a superconducting quantum interference device (SQUID) magnetometer. Implantation of the Co particles by Pt or Xe ions produced a large anisotropic increase in their coercivity. Accordingly, these magnetic nanoparticle systems may be of interest for magnetic data storage applications. Details of the magnetic properties of the Co/Al2O3 nanocomposites including their retentivity, coercivity, saturation field, and magnetic anisotropy are presented.

Formation of Au-nanocrystals in TiO2 and SrTiO3 by ion implantation in restricted volumes

2003 ◽  
Vol 792 ◽  
Author(s):  
R. Fromknecht ◽  
G. Linker ◽  
K. Sun ◽  
S. Zhu ◽  
L.M. Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Ion Implantation ◽  
Dose Rate ◽  
Size Distribution ◽  
Average Particle Size ◽  
Surface Region ◽  
High Dose ◽  
Average Particle ◽  
Tem Analysis ◽  
Near Surface

ABSTRACTAu-ions were implanted at RT conventionally and through a mask into TiO2- and SrTiO3-single crystals with doses in the range from 1×1015Au+/cm2 to 1×1017Au+/cm2, and dose rates of ∼1011ions/sec and ∼3×1013ions/sec, at an energy of 260keV; some samples subsequently were annealed at temperatures up to 1100K. The Au-atoms precipitated to nanocrystals during implantation with an average particle size of 1.5nm. HRTEM investigations revealed that the Au-nanocrystals, embedded in amorphous TiO2-regions, have a broad size distribution varying from large sizes in the near surface region to smaller sizes at larger depths. In the annealing process a coarsening and a reorientation of the Au-nanocrystals is observed. At 1000K the particle size of the textured Au-implant was evaluated to be ∼6nm. Implantation with a high dose rate performed through a metal mask with holes of 120μm diameter and without annealing resulted in an almost equidistant arrangement of the Au-nanocrystals with a narrow size distribution of 2–6nm in TiO2 and 3–5nm in SrTiO3 in the near surface region. Au-ion implantation through an e-beam resist mask (50nm × 50nm holes), with doses ranging from 1×1015Au+/cm2 to 4×1015Au+/cm2 at the low dose rate and annealed at 1000K, lead to a periodic structure of the Au-nanocrystals. The nanocrystal size, evaluated from TEM analysis, in the as-implanted state was ∼5nm and after annealing at 1000K sizes of several nanometers to several tens of nanometers were observed.

The Effects of Ion Implantation on the Surface Features of Inconel 600

1985 ◽  
Vol 43 ◽  
pp. 288-289
Author(s):  
John D. Rubio
Keyword(s):  
Grain Boundary ◽  
Ion Implantation ◽  
Nuclear Power ◽  
Power Plants ◽  
Surface Region ◽  
Selective Dissolution ◽  
Boundary Region ◽  
Near Surface ◽  
Inconel 600 ◽  
Steam Generator Tubing

The degradation of steam generator tubing at nuclear power plants has become an important problem for the electric utilities generating nuclear power. The material used for the tubing, Inconel 600, has been found to be succeptible to intergranular attack (IGA). IGA is the selective dissolution of material along its grain boundaries. The author believes that the sensitivity of Inconel 600 to IGA can be minimized by homogenizing the near-surface region using ion implantation. The collisions between the implanted ions and the atoms in the grain boundary region would displace the atoms and thus effectively smear the grain boundary.To determine the validity of this hypothesis, an Inconel 600 sample was implanted with 100kV N2+ ions to a dose of 1x1016 ions/cm2 and electrolytically etched in a 5% Nital solution at 5V for 20 seconds. The etched sample was then examined using a JEOL JSM25S scanning electron microscope.

scholarly journals Microstructure and Mechanical Properties of Ti + N Ion Implanted Cronidur30 Steel

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 427 ◽  
Author(s):  
Jie Jin ◽  
Wei Wang ◽  
Xinchun Chen
Keyword(s):  
Mechanical Properties ◽  
Ion Implantation ◽  
Photoelectron Spectroscopy ◽  
Structural Modification ◽  
Surface Region ◽  
Grazing Incidence ◽  
Bearing Steel ◽  
Near Surface ◽  
X Ray ◽  
Ion Implanted

In this study, Ti + N ion implantation was used as a surface modification method for surface hardening and friction-reducing properties of Cronidur30 bearing steel. The structural modification and newly-formed ceramic phases induced by the ion implantation processes were investigated by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and grazing incidence X-ray diffraction (GIXRD). The mechanical properties of the samples were tested by nanoindentation and friction experiments. The surface nanohardness was also improved significantly, changing from ~10.5 GPa (pristine substrate) to ~14.2 GPa (Ti + N implanted sample). The friction coefficient of Ti + N ion implanted samples was greatly reduced before failure, which is less than one third of pristine samples. Furthermore, the TEM analyses confirmed a trilamellar structure at the near-surface region, in which amorphous/ceramic nanocrystalline phases were embedded into the implanted layers. The combined structural modification and hardening ceramic phases played a crucial role in improving surface properties, and the variations in these two factors determined the differences in the mechanical properties of the samples.

Modification of The Near-Surface Region Of Al2O3 By Ion Implantation

1983 ◽  
Vol 24 ◽  
Author(s):  
C. W. White ◽  
G. C. Farlow ◽  
H. Naramoto ◽  
C. J. Mchargue ◽  
B. R. Appleton
Keyword(s):  
Mechanical Properties ◽  
Ion Implantation ◽  
Thermal Annealing ◽  
Structural Property ◽  
Surface Region ◽  
Impurity Incorporation ◽  
Near Surface ◽  
Implantation Damage ◽  
Property Changes

ABSTRACTPhysical and structural property changes resulting from ion implantation and thermal annealing of α-A12O3 are reviewed. Emphasis is placed on damage production during implantation, damage recovery during thermal annealing, and impurity incorporation during thermal annealing. Physical and structural property changes caused by ion implantation and annealing are correlated with changes in the mechanical properties.

Short-range ordering of Cu3Au above Tc in the topmost 80 A of a (001) face

1997 ◽  
Vol 12 (1) ◽  
pp. 75-82 ◽  
Author(s):  
M. Kimura ◽  
J. B. Cohen ◽  
S. Chandavarkar ◽  
K. Liang
Keyword(s):  
Short Range ◽  
Short Range Order ◽  
Surface Region ◽  
Antiphase Domain ◽  
Range Order ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Diffuse Intensity ◽  
Near Surface ◽  
Atomic Displacements

The short-range order in the near surface region of the Cu3Au(001) face was investigated above the critical temperature by glancing-incidence x-ray diffraction, measuring the diffuse intensity throughout a two-dimensional region of reciprocal space. This intensity was analyzed quantitatively to obtain the two-dimensional Cowley–Warren short-range-order parameters and atomic displacements. Monte-Carlo simulation based on these values has revealed that the atomic configurations in the surface consist of ordered domains and clusters in a disordered matrix. There is a large number of {10} antiphase domain boundaries (APDB).

Characterization of Reactive Ion Etch Damage in GaAs by Triple Crystal X-Ray Diffraction

1993 ◽  
Vol 324 ◽  
Author(s):  
Victor S. Wang ◽  
Richard J. Matyi ◽  
Karen J. Nordheden
Keyword(s):  
Bias Voltage ◽  
Diffuse Scattering ◽  
Reciprocal Lattice ◽  
Surface Region ◽  
Perfect Crystal ◽  
X Ray Diffraction ◽  
Reciprocal Lattice Point ◽  
Near Surface ◽  
X Ray ◽  
Imperfect Crystal

AbstractTriple crystal x-ray diffraction (TCXD) is a non-destructive structural characterization tool capable of the separation and direct observation of the dynamic (perfect crystal) and the kinematic (imperfect crystal) components of the total intensity diffracted by a crystal. Specifically, TCXD can be used to measure the magnitude of the diffuse scattering arising from defects in the crystal structure in the immediate vicinity of a reciprocal lattice point. In this study, the effects of BC13 reactive ion etching (RIE) on the near-surface region of GaAs were investigated by analyzing the changes in the diffuse scattering using both the symmetric 004 reflection as well as the highly asymmetric and more surface sensitive 113 reflection. While the results from the 004 reflections revealed little difference between the unetched and the BC13-etched samples, maps of the diffracted intensity around the 113 reflections showed an unexpected and reproducible decrease in the extent of the diffuse scattering in the transverse direction (perpendicular to the < 113 > direction) as the RIE bias voltage was increased. This decrease suggests that the degree of etch damage induced in the GaAs near-surface region is reduced with increasing bias voltage and ion energy. Additionally, the symmetry and orientation of the kinematic scattering was altered. Possible mechanisms for these results willbe discussed.

Microstructure and Oxidation of a Cast Nickel Aluminide Alloy

2002 ◽  
Vol 753 ◽  
Author(s):  
D. Y. Lee ◽  
M. L. Santella ◽  
I. M. Anderson ◽  
G. M. Pharr
Keyword(s):  
Nickel Aluminide ◽  
Volume Fraction ◽  
Surface Region ◽  
Oxidation Products ◽  
Al Alloy ◽  
X Ray Diffraction ◽  
Multivariate Statistical ◽  
Near Surface ◽  
X Ray ◽  
Spectrum Imaging

ABSTRACTSpecimens of the cast Ni3Al alloy IC221M were annealed in air at 900°C to examine the effects of oxidation and thermal aging on the microstructure. The alloy is comprised of a dendritically solidified γ-γ′ matrix containing γ+Ni5Zr eutectic colonies in the interdendritic regions. Microstructures of aged specimens were examined by optical microscopy and energy dispersive X-ray (EDX) spectrum imaging in the scanning electron microscope (SEM). Two primary changes in the microstructures were observed: (1) there is considerable homogenization of the cast microstructures with aging, and (2) the volume fraction of the γ+Ni5Zr eutectic decreases. Oxidation products were identified using x-ray diffraction and EDX spectrum imaging with multivariate statistical analysis (MSA). During the initial stages of oxidation, the first surface oxide to form is mostly NiO with small amounts of Cr2O3, ZrO2, NiCr2O4, and θ-Al2O3. Initially, oxidation occurs primarily in the interdendritic regions due to microsegregation of alloying elements during casting. With further aging, a continuous film of α-Al2O3 forms immediately beneath the surface that eventually evolves into a double layer of α-Al2O3 and NiAl2O4. Although these oxides are constrained to the near surface region, others penetrate to greater depths facilitated by oxidation of the γ+Ni5Zr eutectic colonies. These oxides appear in the microstructure as long, thin spikes of ZrO2 surrounded by a thin sheath of Al2O3.

Effects of Silicon Ion Implantation upon Thin Gate Oxide Integrity

1992 ◽  
Vol 262 ◽  
Author(s):  
G. -S. Lee ◽  
J. -G. Park ◽  
S. -P. Choi ◽  
C. -H. Shin ◽  
Y. -B. Sun ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Dielectric Breakdown ◽  
Defect Density ◽  
Surface Region ◽  
Gate Oxide ◽  
Near Surface ◽  
Time Dependent Dielectric Breakdown ◽  
Thin Gate Oxide ◽  
Si Ion Implantation ◽  
Gate Oxide Integrity

ABSTRACTIn this study, using oxide breakdown voltage and time-dependent-dielectric breakdown measurements, thermal wave modulated reflectance and chemical etching/optical microscopy, we investigated effects of Si ion implantation upon formation of D-defects and thin gate oxide integrity. Our data show that addition of Si ion implantation with a dose of up to 1013 ions/cm2 improves oxide integrity if the implantation is done at a certain step just before sacrificial oxidation in the Mb DRAM process. However, no improvement in oxide integrity is observed when the same implantation is done on the virgin wafer surfaces at the start of the same Mb DRAM process. We discuss our hypothesis that the improvement in oxide integrity is due to a reduction in the D-defect density in the near-surface region of the wafer.

In situ X-ray diffraction study of stacking fault formation in the near-surface region of transformation induced plasticity steels

2013 ◽  
Vol 530 ◽  
pp. 105-112 ◽  
Author(s):  
David Rafaja ◽  
Christina Krbetschek ◽  
Daria Borisova ◽  
Gerhard Schreiber ◽  
Volker Klemm
Keyword(s):  
Diffraction Study ◽  
Surface Region ◽  
Stacking Fault ◽  
X Ray Diffraction ◽  
Near Surface ◽  
Transformation Induced Plasticity ◽  
X Ray
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