Mechanism of FIB-Induced Phase Transformation in Austenitic Steel

2021 ◽  
pp. 1-13
Author(s):  
Joseph R. Michael ◽  
Lucille A. Giannuzzi ◽  
M. Grace Burke ◽  
Xiang Li Zhong
Keyword(s):  
Ion Irradiation ◽  
Ion Beam ◽  
Transformation Product ◽  
304 Stainless Steel ◽  
Orientation Relationships ◽  
Austenite Grain ◽  
Beam Sample ◽  
Bcc Phase ◽  
Ion Species ◽  
Unstable Austenite

The transformation of unstable austenite to ferrite or α′ martensite as a result of exposure to Xe+ or Ga+ ions at room temperature was studied in a 304 stainless steel casting alloy. Controlled Xe+ and Ga+ ion beam exposures of the 304 were carried out at a variety of beam/sample geometries. It was found that both Ga+ and Xe+ ion irradiation resulted in the transformation of the austenite to either ferrite or α′ martensite. In this paper, we will refer to the transformation product as a BCC phase. The crystallographic orientation of the transformed area was controlled by the orientation of the austenite grain and was consistent with either the Nishiyama–Wasserman or the Kurdjumov–Sachs orientation relationships. On the basis of the Xe+ and Ga+ ion beam exposures, the transformation is not controlled by the chemical stabilization of the BCC phase by the ion species, but is a result of the disorder caused by the ion-induced recoil motion and subsequent return of the disordered region to a more energetically favorable phase.

Ion Beam Assisted Quantum well Intermixing

1995 ◽  
Vol 396 ◽  
Author(s):  
R. D. Goldberg ◽  
I. V. Mitchell ◽  
S. Charbonneau ◽  
P. Poole ◽  
E. S. Koteles ◽  
...  
Keyword(s):  
Quantum Well ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Multiple Quantum Well ◽  
High Energy ◽  
Multiple Quantum ◽  
Active Components ◽  
Quantum Well Structures ◽  
Ion Species ◽  
Made In

AbstractSignificant progress has been made in the past year in the use of high energy (MeV) ion irradiation to tune the bandgap and therefore emission wavelengths of single and multiple quantum well structures. These shifts are attributable to compositional mixing across the well and barrier layer interfaces, a process that is driven by the vacancy flux, released during the anneal stage, from radiation defects. We present data from a series of measurements in both GaAs- and InP-based QW structures to demonstrate the importance of the implantation parameters chosen (ion species, energy, flux, fluence and implant temperature). The dramatic difference in the response of these two systems with regard to the implant depth is believed to be associated with the very different diffusivities of the Gp III site vacancies. Prospects for implementing the irradiation approach as a spatially selective, planar process in integrated optoelectronic circuitry look very attractive and are illustrated for both passive and active components by reference to recent results from tuned wavelength lasers.

Temperature Dependence of DC Conductivity in Ion-Beam-Irradiated Glassy Carbon

1990 ◽  
Vol 201 ◽  
Author(s):  
Dougal McCulloch ◽  
Steven Prawer
Keyword(s):  
Electrical Conductivity ◽  
Temperature Dependence ◽  
Glassy Carbon ◽  
Ion Irradiation ◽  
Functional Dependence ◽  
Ion Beam ◽  
Variable Range Hopping ◽  
Beam Irradiation ◽  
Ion Beam Irradiation ◽  
Ion Species

AbstractThe electrical conductivity of ion beam irradiated Glassy Carbon has been investigated in the temperature range 100 to 300 K. Ion species used were C+ and N+ with doses between 1014 and 1018 ions/cm2. Ion beam irradiation was found to lower the conductivity of Glassy Carbon by up to six orders of magnitude. The temperature dependence of the conductivity in ion beam modified Glassy Carbon has been measured. The functional dependence was found to remain largely unchanged by ion irradiation despite the large overall decrease in the conductivity. The results are interpreted in terms of a model which includes a variable range hopping and strongly scattering metallic components.

Transmission Electron Microscopy of Martensitic Transformation in Xe-implanted Austenitic 304 Stainless Steel

2005 ◽  
Vol 20 (7) ◽  
pp. 1751-1757 ◽  
Author(s):  
Guoqiang Xie ◽  
Minghui Song ◽  
Kazutaka Mitsuishi ◽  
Kazuo Furuya
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stainless Steel ◽  
Phase Transformation ◽  
Steel Specimen ◽  
304 Stainless Steel ◽  
Face Centered Cubic ◽  
Orientation Relationships ◽  
Transmission Electron ◽  
Bcc Phase

Thin film specimens of austenitic 304 stainless steel implanted with 100 keV Xe ions at room temperature were investigated. Microstructural evolution and phase transformation were characterized and analyzed in situ with conventional and high-resolution transmission electron microscopy. The phase transformation in a sequence from austenitic γ face-centered cubic (fcc) to hexagonal close-packed (hcp), and then to a martensitic α body-centered cubic (bcc) structure was observed in the implanted specimens. The fraction of the induced α(bcc) phase increased with increasing Xe ion fluence. Orientation relationships between the induced α(bcc) phase and austenitic γ(fcc) matrix were determined to be (011)α//(111)γ and [111]α//[011]γ. The relationship was independent of the induced process of the martensitic phase transformation for austenitic 304 stainless steel specimen, in agreement with the Kurdjumov–Sachs (K-S) rule. It is suggested that the phase transformation is induced mainly by the formation of the highly pressurized Xe precipitates, which generate a large stress level in stainless steels.

Ion Beams for synthesis and modification of nanostructures in semiconductors

2011 ◽  
Vol 1354 ◽  
Author(s):  
Anand P. Pathak ◽  
N. Srinivasa Rao ◽  
G. Devaraju ◽  
V. Saikiran ◽  
S. V. S. Nageswara Rao
Keyword(s):  
Quantum Wells ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Rf Magnetron Sputtering ◽  
Heavy Ion ◽  
Swift Heavy Ion Irradiation ◽  
Heavy Ion Irradiation ◽  
Swift Heavy Ion ◽  
Beam Parameters ◽  
Ion Species

ABSTRACTSwift heavy ion irradiation is one of the most versatile techniques to alter and monitor the properties of materials in general and at nanoscale in particular. The materials modification can be controlled by a suitable choice of ion beam parameters such as ion species, fluence and incident energy. It is also possible to choose these ion beam parameters in such a way that ion beam irradiation can cause annealing of defects or creation of defects at a particular depth. Here, we present a review of our work on swift heavy ion induced modifications of III-V semiconductor heterostructures and multi-quantum wells in addition to synthesis of Ge nanocrystals using atom beam co-sputtering, RF magnetron sputtering followed by RTA, swift heavy ion irradiation, respectively. We also present the growth of GeO2 nanocrystals by microwave annealing. These samples were studied by using XRD, Raman, PL, RBS and TEM. The observed results and their explanation using possible mechanisms are discussed in detail.

Electron and ion irradiation-induced dissolution of mechanical twins in the intermetalic U3Si: An in situ HVEM study

1989 ◽  
Vol 47 ◽  
pp. 652-653
Author(s):  
Charles W. Allen ◽  
Robert C. Birtcher
Keyword(s):  
Elevated Temperatures ◽  
Ion Irradiation ◽  
Ion Beam ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Heavy Ion ◽  
High Energy ◽  
Mechanical Twinning ◽  
In Situ Experiments

The uranium silicides, including U3Si, are under study as candidate low enrichment nuclear fuels. Ion beam simulations of the in-reactor behavior of such materials are performed because a similar damage structure can be produced in hours by energetic heavy ions which requires years in actual reactor tests. This contribution treats one aspect of the microstructural behavior of U3Si under high energy electron irradiation and low dose energetic heavy ion irradiation and is based on in situ experiments, performed at the HVEM-Tandem User Facility at Argonne National Laboratory. This Facility interfaces a 2 MV Tandem ion accelerator and a 0.6 MV ion implanter to a 1.2 MeV AEI high voltage electron microscope, which allows a wide variety of in situ ion beam experiments to be performed with simultaneous irradiation and electron microscopy or diffraction.At elevated temperatures, U3Si exhibits the ordered AuCu3 structure. On cooling below 1058 K, the intermetallic transforms, evidently martensitically, to a body-centered tetragonal structure (alternatively, the structure may be described as face-centered tetragonal, which would be fcc except for a 1 pet tetragonal distortion). Mechanical twinning accompanies the transformation; however, diferences between electron diffraction patterns from twinned and non-twinned martensite plates could not be distinguished.

scholarly journals Comparison of short-range order in irradiated dysprosium titanates

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Roman Sherrod ◽  
Eric C. O’Quinn ◽  
Igor M. Gussev ◽  
Cale Overstreet ◽  
Joerg Neuefeind ◽  
...  
Keyword(s):  
Long Range ◽  
Short Range ◽  
Structural Model ◽  
Ion Irradiation ◽  
Function Analysis ◽  
Ion Beam ◽  
Structural Response ◽  
Heavy Ion ◽  
Range Order ◽  
Radiation Resistant

AbstractThe structural response of Dy2TiO5 oxide under swift heavy ion irradiation (2.2 GeV Au ions) was studied over a range of structural length scales utilizing neutron total scattering experiments. Refinement of diffraction data confirms that the long-range orthorhombic structure is susceptible to ion beam-induced amorphization with limited crystalline fraction remaining after irradiation to 8 × 1012 ions/cm2. In contrast, the local atomic arrangement, examined through pair distribution function analysis, shows only subtle changes after irradiation and is still described best by the original orthorhombic structural model. A comparison to Dy2Ti2O7 pyrochlore oxide under the same irradiation conditions reveals a different behavior: while the dysprosium titanate pyrochlore is more radiation resistant over the long-range with smaller degree of amorphization as compared to Dy2TiO5, the former involves more local atomic rearrangements, best described by a pyrochlore-to-weberite-type transformation. These results highlight the importance of short-range and medium-range order analysis for a comprehensive description of radiation behavior.

Back calculation of parent austenite orientation using a clustering approach

2013 ◽  
Vol 46 (1) ◽  
pp. 210-215 ◽  
Author(s):  
V. Tari ◽  
A. D. Rollett ◽  
H. Beladi
Keyword(s):  
Face Centered Cubic ◽  
Orientation Relationships ◽  
New Approach ◽  
Austenite Grain ◽  
Parent Orientation ◽  
Back Calculation ◽  
Clustering Approach ◽  
Face Centered ◽  
Parent Austenite ◽  
Good Agreement

A new approach is presented for calculating the parent orientation from sets of variants of orientations produced by phase transformation. The parent austenite orientation is determined using the orientations of bainite variants that transformed from a single parent austenite grain. In this approach, the five known orientation relationships are used to back transform each observed bainite variant to all their potential face-centered-cubic (f.c.c.) parent orientations. A set of potential f.c.c. orientations has one representative from each bainite variant, and each set is assembled on the basis of minimum mutual misorientation. The set of back-transformed orientations with the minimum summation of mutual misorientation angle (SMMA) is selected as the most probable parent (austenite) orientation. The availability of multiple sets permits a confidence index to be calculated from the best and next best fits to a parent orientation. The results show good agreement between the measured parent austenite orientation and the calculated parent orientation having minimum SMMA.

SPUTTERING WITH GAS CLUSTER-ION BEAMS

1996 ◽  
Vol 03 (01) ◽  
pp. 1017-1021 ◽  
Author(s):  
J. MATSUO ◽  
M. AKIZUKI ◽  
J. NORTHBY ◽  
G.H. TAKAOKA ◽  
I. YAMADA
Keyword(s):  
Ion Irradiation ◽  
Removal Rate ◽  
Ion Beam ◽  
Solid Surfaces ◽  
Silicon Surfaces ◽  
Cluster Ions ◽  
Mass Filter ◽  
Cluster Bombardment ◽  
Cluster Ion Beams ◽  
Cluster Ion

A high-current (~100 nA) cluster-ion-beam equipment with a new mass filter has been developed to study the energetic cluster-bombardment effects on solid surfaces. A dramatic reduction of Cu concentration on silicon surfaces has been achieved by 20-keV Ar cluster (N~3000) ion bombardment. The removal rate of Cu with cluster ions is two orders of magnitude higher than that with monomer ions. A significantly higher sputtering yield is expected for cluster-ion irradiation. An energetic cluster-ion beam is quite suitable for removal of metal.

Growth of Cu-Oxide Protrusion by Ar Ion Irradiation

2007 ◽  
Vol 558-559 ◽  
pp. 1359-1362 ◽  
Author(s):  
Hiroyuki Tanaka ◽  
Shunichiro Tanaka
Keyword(s):  
Ion Irradiation ◽  
Ion Beam ◽  
Beam Irradiation ◽  
Ion Beam Irradiation ◽  
Residual Oxygen ◽  
Irradiation Angle ◽  
Oxygen Atoms

Cu2O conical micron-scale protrusions have been grown on a preoxidized Cu surface by the Ar ion beam irradiation at 9 kV for 5-20 min in the low vacuum. This Ar ion irradiation is based on the ‘Transcription Method’ which has been originated by B.-S. Xu and S.-I. Tanaka in 1996 to form nanoparticles. Ar ion irradiation induced needle-like nanostructures composed of Cu2O and CuO which were randomly nucleated on Cu surface by the oxidation at 623 K for 10 min in the air. The obtained Cu2O conical protrusions have a controllable length of up to 14.6 μm with diameter in the range of 0.8 μm by changing the Ar ion irradiation angle to the surface. The mechanism of the formation of the conical protrusions is proposed that Cu atoms on the Cu surface activated and sputtered by the Ar ion irradiation diffuse on the surface of needle-like oxide as nuclei along the Ar ion track and react with residual oxygen atoms to grow the conical Cu2O protrusions.

Photon and Ion Beam-Induced Chemistry of Palladium Acetate Films

1986 ◽  
Vol 75 ◽  
Author(s):  
M. E. Gross ◽  
W. L. Brown ◽  
J. Linnros ◽  
L. R. Harriott ◽  
K. D. Cummings ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Decomposition Reaction ◽  
Palladium Acetate ◽  
Metallic Silver ◽  
Electrically Conducting ◽  
Reaction Fronts ◽  
Explosive Reaction ◽  
Palladium Particles

AbstractElectrically conducting palladium features have been produced by laser and ion beam irradiation of thin palladium acetate films. The photothermal reaction induced by scanned continuous wave Ar+ laser irradiation leads to metal lines that may exhibit periodic structure. This results from repeated propagation of “explosive” reaction fronts generated by coupling of the heat from the absorbed laser radiation with the heat of the decomposition reaction of the film. In contrast, 2 MeV He+ ion irradiation produces smooth metallic-looking features that contain up to 20% of the original carbon and 5% of the original oxygen content of the film. Films irradiated with 2 MeV Ne+ ions contain slightly lower amounts of carbon and oxygen residues, but fully exposed thick films (0.90 μm) appear black rather than metallic silver. In addition to having significantly higher purity, the laser-written features have lower resistivities than the ion beam-irradiated features. Infrared spectroscopy of the ion beam-irradiated films as a function of dose indicates a progressive loss in intensity of the characteristics acetate (COO-) vibrations. This occurs at doses lower than those associated with major C and O loss from the films. Partially ion-exposed films continue to decompose to metallic-looking material over a period of weeks after irradiation. Metallic palladium particles apparently catalyze this process.

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