A SURFACE X-RAY DIFFRACTION STUDY OF THE GROWTH OF ULTRATHIN LAYERS OF Fe ON Cu(001)

Although it is well known that the γ (fcc) phase of Fe can be stabilised on Cu(001) single crystal substrates, there is still considerable disagreement about the exact nature of the growth mode and the structures that evolve with increasing film thickness. A detailed knowledge of the structure and morphology is essential for a complete understanding of the magnetic properties of ultrathin iron films. Surface X-ray diffraction measurements, recorded in real time during deposition of Fe deposition on Cu(001), are presented. At room temperature, well-defined layer-by-layer growth, with no significant agglomeration of iron, was observed. The specular intensity of the X-ray beam varied parabolically with coverage, as predicted by kinematical theory. Intensity oscillations were observed up to 15 Fe monolayers, at which coverage relaxation to the α (bcc) phase was confirmed. At 85 K the growth is diffusion limited.

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Growth of CaFeOX/LaFeO3 Superlattice on SrTiO3(100) Substrates

MRS Proceedings ◽

10.1557/opl.2011.245 ◽

2011 ◽

Vol 1292 ◽

Cited By ~ 3

Author(s):

Nobuyuki Iwata ◽

Mark Huijben ◽

Guus Rijnders ◽

Hiroshi Yamamoto ◽

Dave H. A. Blank

Keyword(s):

Thin Films ◽

Pulsed Laser Deposition ◽

Pulsed Laser ◽

Layer Growth ◽

Laser Deposition ◽

Growth Mode ◽

Layer By Layer ◽

X Ray Diffraction ◽

Reciprocal Space Mapping ◽

X Ray

ABSTRACTThe CaFeOX(CFO) and LaFeO3(LFO) thin films as well as superlattices were fabricated on SrTiO3(100) substrates by pulsed laser deposition (PLD) method. The tetragonal LFO film grew with layer-by-layer growth mode until approximately 40 layers. In the case of CFO, initial three layers showed layer-by-layer growth, and afterward the growth mode was transferred to two layers-by-two layers (TLTL) growth mode. The RHEED oscillation was observed until the end of the growth, approximately 50nm. Orthorhombic twin CaFeO2.5 (CFO2.5) structure was obtained. However, it is expected that the initial three CFO layers are CaFeO3 (CFO3) with the valence of Fe4+. The CFO and LFO superlattice showed a step-terraces surface, and the superlattice satellite peaks in a 2θ-θ and reciprocal space mapping (RSM) x-ray diffraction (XRD) measurements, indicating that the clear interfaces were fabricated.

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Growth twins in Bi2Ca1Sr2Cu2O8 superconductor single crystals

Journal of Materials Research ◽

10.1557/jmr.1990.0909 ◽

1990 ◽

Vol 5 (5) ◽

pp. 909-912 ◽

Cited By ~ 7

Author(s):

P. D. Han ◽

A. Asthana ◽

Z. Xu ◽

D. A. Payne

Keyword(s):

Electron Microscopy ◽

Crystal Growth ◽

Large Scale ◽

Layer Growth ◽

Layer By Layer ◽

X Ray Diffraction ◽

Growth Morphology ◽

X Ray ◽

Twin Formation ◽

First Time

Large-scale twin structures in single crystal Bi2Ca1Sr2Cu2O8 (2122) are reported for the first time. Symmetrical 90° (i.e., a-b) twins with a [110] type twin boundary were observed. A characteristic layer-growth morphology and jagged twin walls suggest that twin formation occurred layer by layer during crystal growth; i.e., the twins were growth twins. Hot-stage optical microscopy, x-ray diffraction, and electron microscopy results are discussed with reference to twin morphology.

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How heteroepitaxy occurs on strontium titanate

Science Advances ◽

10.1126/sciadv.aav0764 ◽

2019 ◽

Vol 5 (4) ◽

pp. eaav0764 ◽

Cited By ~ 2

Author(s):

Seyoung Cook ◽

Kendra Letchworth-Weaver ◽

I-Cheng Tung ◽

Tassie K. Andersen ◽

Hawoong Hong ◽

...

Keyword(s):

Critical Role ◽

Substrate Material ◽

Layer Growth ◽

Perovskite Oxide ◽

Layer By Layer ◽

Heteroepitaxial Growth ◽

X Ray Diffraction ◽

X Ray ◽

Highly Active ◽

Oxide Substrate

In traditional models of heteroepitaxy, the substrate serves mainly as a crystalline template for the thin-film lattice, dictating the initial roughness of the film and the degree of coherent strain. Here, performing in situ surface x-ray diffraction during the heteroepitaxial growth of LaTiO3 on SrTiO3 (001), we find that a TiO2 adlayer composed of the (13×13)R33.7° and (2×2)R45.0° reconstructions is a highly active participant in the growth process, continually diffusing to the surface throughout deposition. The effects of the TiO2 adlayer on layer-by-layer growth are investigated using different deposition sequences and anomalous x-ray scattering, both of which permit detailed insight into the dynamic layer rearrangements that take place. Our work challenges commonly held assumptions regarding growth on TiO2-terminated SrTiO3 (001) and demonstrates the critical role of excess TiO2 surface stoichiometry on the initial stages of heteroepitaxial growth on this important perovskite oxide substrate material.

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Layer-by-layer growth of GaAs() studied by in situ synchrotron X-ray diffraction

Surface Science ◽

10.1016/s0039-6028(02)02551-7 ◽

2003 ◽

Vol 525 (1-3) ◽

pp. 126-136 ◽

Cited By ~ 21

Author(s):

Wolfgang Braun ◽

Bernd Jenichen ◽

Vladimir M. Kaganer ◽

Alexander G. Shtukenberg ◽

Lutz Däweritz ◽

...

Keyword(s):

Layer Growth ◽

Layer By Layer ◽

X Ray Diffraction ◽

X Ray

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Mbe Growth and Thermoelectric Properties OF Bi2Te3 Thin Films

MRS Proceedings ◽

10.1557/proc-545-183 ◽

1998 ◽

Vol 545 ◽

Author(s):

Sunglae Cho ◽

Yunki Kim ◽

Antonio DiVenere ◽

George K. L. Wong ◽

Jerry R. Meyer ◽

...

Keyword(s):

Thin Films ◽

Antisite Defect ◽

High Energy ◽

Layer Growth ◽

Layer By Layer ◽

X Ray Diffraction ◽

Mbe Growth ◽

X Ray ◽

Crystal Bulk

AbstractWe have grown high quality Bi2Te3 thin films on CdTe(111)B substrates using MBE. Structural properties have been investigated using in-situ reflection high-energy electron diffraction (RHEED) and θ-2θ X-ray diffraction analysis. They show that Bi2Te3films on CdTe(111) grow along the (00.l) in the hexagonal cell with a layer-by-layer growth mode, resulting in a smooth surface, and an X-ray Bragg peak FWHM of 0.2°. The thermopower and electrical conductivity of the stoichiometric Bi2Te3 films were ∼200 μV/K and 103(Ωcm)−1, respectively, comparable to the single crystal bulk values. We have observed the antisite defect effect in Te-rich Bi2Te3films: excess Te occupies Bi lattice sites and behaves as an n-type dopant. Crystallinity and transport properties are strongly affected by non-stoichiometry.

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Synthesis and Characterization of Zn Oxide Hexagonal Nano-Pole Films on Quartz Glass Substrate

International Journal of Chemical Reactor Engineering ◽

10.2202/1542-6580.2051 ◽

2009 ◽

Vol 7 (1) ◽

Author(s):

Jie Chen ◽

Jun Wang

Keyword(s):

Growth Mechanism ◽

Quartz Glass ◽

Photoelectron Spectroscopy ◽

Glass Substrate ◽

Sol Gel ◽

Layer Growth ◽

Layer By Layer ◽

Quartz Glass Substrate ◽

Wurtzite Phase ◽

X Ray

Hexagon-shaped Zn oxide nano-pole films with terraces and steps have been successfully fabricated by means of a combined approach involving sol-gel process, high-temperature heat treatment, and the hydrothermal method. The surface chemistry and morphological features of the films were characterized by means of x-ray photoelectron spectroscopy and scanning electron microcopy. All the diffraction peaks in x-ray diffraction pattern match with those of the hexagonal wurtzite phase of Zn oxide. Transmittance measurements show that the optical transmittance of the sample synthesized at 520°C on quartz glass substrate is the highest, reaching about 65% in the visible-light region. Based on the detailed structural characterization and the nucleation-growth kinetics, we find that the whole crystallization process of wurtzite Zn oxide nano-poles includes nanocatalysis and layer-by-layer growth mechanism. The present study provides an important understanding of the growth mechanism for nano-pole synthesis of Zn oxide and related materials.

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Initial Growth and Crystallization Onset of Plasma Enhanced-Atomic Layer Deposited ZnO

Crystals ◽

10.3390/cryst10040291 ◽

2020 ◽

Vol 10 (4) ◽

pp. 291

Author(s):

Alberto Perrotta ◽

Julian Pilz ◽

Roland Resel ◽

Oliver Werzer ◽

Anna Maria Coclite

Keyword(s):

Atomic Layer ◽

Layer Growth ◽

Growth Mode ◽

Ex Situ ◽

Native Oxide ◽

Layer By Layer ◽

Initial Growth ◽

Island Growth ◽

X Ray ◽

Crystallization Onset

Direct plasma enhanced-atomic layer deposition (PE-ALD) is adopted for the growth of ZnO on c-Si with native oxide at room temperature. The initial stages of growth both in terms of thickness evolution and crystallization onset are followed ex-situ by a combination of spectroscopic ellipsometry and X-ray based techniques (diffraction, reflectivity, and fluorescence). Differently from the growth mode usually reported for thermal ALD ZnO (i.e., substrate-inhibited island growth), the effect of plasma surface activation resulted in a substrate-enhanced island growth. A transient region of accelerated island formation was found within the first 2 nm of deposition, resulting in the growth of amorphous ZnO as witnessed with grazing incidence X-ray diffraction. After the islands coalesced and a continuous layer formed, the first crystallites were found to grow, starting the layer-by-layer growth mode. High-temperature ALD ZnO layers were also investigated in terms of crystallization onset, showing that layers are amorphous up to a thickness of 3 nm, irrespective of the deposition temperature and growth orientation.

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A microstructural and corrosion resistance study of (Zr, Si, Ti)N-Ni coatings produced through co-sputtering

DYNA ◽

10.15446/dyna.v85n207.73304 ◽

2018 ◽

Vol 85 (207) ◽

pp. 192-197 ◽

Cited By ~ 1

Author(s):

Estrella Natali Borja-Goyeneche ◽

Jhon Jairo Olaya-Florez

Keyword(s):

Corrosion Resistance ◽

Nickel Content ◽

Corrosion Current ◽

Nacl Solution ◽

X Ray Diffraction ◽

X Ray ◽

X Ray Scattering ◽

Current Densities ◽

Fcc Phase

This work researches the influence of the nickel content on the structural and anticorrosive properties of ZrSiTiN films deposited by means of reactive co-sputtering on alloys of Ti6Al4V. The morphology and structure were analyzed by means of scanning electron microscopy (SEM) and X-ray diffraction (XRD), and the chemical composition was identified via X-ray scattering spectroscopy (EDS). The corrosion resistance was studied using potentiodynamic polarization (PP) tests employing a 3.5% by weight NaCl solution. In the films, an increase of Ni up to 6.97 at% was observed, while in XRD the FCC phase of (Zr, Ti) N was identified, with a mixed orientation in planes (111) and (200), which tended to diminish with the increase of Ni. Finally, with the addition of Ni, the corrosion current densities were reduced from 5.56 𝑥 10−8 to 2.64 𝑥 10−9 𝐴/𝑐m2. The improvement in the corrosion resistance is due to the effect of the Ni on the microstructure of the system (Zr, Ti) N, which can improve the quality of the passive film and prevent crystalline defects and corrosion zones.

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New insights into the nature of glauconite

American Mineralogist ◽

10.2138/am-2020-7341 ◽

2020 ◽

Vol 105 (5) ◽

pp. 674-686 ◽

Cited By ~ 1

Author(s):

Adrián López-Quirós ◽

Antonio Sánchez-Navas ◽

Fernando Nieto ◽

Carlota Escutia

Keyword(s):

Electron Probe ◽

Layer Growth ◽

Chemical Characteristics ◽

Chemical Analyses ◽

X Ray Diffraction ◽

K Uptake ◽

X Ray ◽

New Findings ◽

Dioctahedral Mica ◽

Interstratified Mineral

Abstract Glauconite must be assessed as mica-rich mica-smectite R3 interstratified mineral, with the pure end-member mica also having intrinsic K-deficient chemical characteristics (K+ ~ 0.8 apfu). This assertion is in accordance with our X-ray diffraction (XRD) and high-resolution tranmission electron microscopy (HRTEM) studies and chemical analyses by electron probe microanalysis (EPMA) of mature glauconites in Cenozoic Antarctic sediments that indicate that: (1) It consists of a glauconite-smectite (R3 ordered) mixed-layer silicate, composed mainly of mica-type layers (>90%), but displaying slightly different proportions of Fe(III)-smectite layers (<10%). (2) More mature glaucony grains are characterized by major K+ and VIFe2+ (mica layers) and minor VIFe3+ (smectite layers) content in the interstratified glauconite-smectite. (3) Potassium is stabilized at the interlayer site by the octahedrally coordinated Fe2+. (4) Microtexture of the glauconite crystals are comparable with those of other micas and illite minerals, with straight, defect-free lattice fringes of ~10 Å spacings glauconite packets characteristic of mica with minor interstratified poorly crystalline smectite layers. In addition, our new findings give insights into the glauconitization process and at the same time investigate the potassium-deficient character of the dioctahedral mica “glauconite.” These findings show that glauconite crystallizes by a layer-growth mechanism at the expense of a poorly crystalline smectite precursor and that smectiteto-glauconite transformations are accompanied by a gradually higher octahedral charge deficiency (Fe2+/Fe3+) stabilized by K+ uptake into the interlayer sheet.

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Layer-by-Layer Self-Assembled Ferrite Multilayer Nanofilms for Microwave Absorption

Journal of Nanomaterials ◽

10.1155/2015/164619 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Jiwoong Heo ◽

Daheui Choi ◽

Jinkee Hong

Keyword(s):

Electron Microscopy ◽

Self Assembly ◽

Precursor Solution ◽

Ferrite Nanoparticles ◽

Energy Dispersive ◽

Layer By Layer ◽

X Ray Diffraction ◽

Simple Method ◽

X Ray ◽

Scanning Electron

We demonstrate a simple method for fabricating multilayer thin films containing ferrite (Co0.5Zn0.5Fe2O4) nanoparticles, using layer-by-layer (LbL) self-assembly. These films have microwave absorbing properties for possible radar absorbing and stealth applications. To demonstrate incorporation of inorganic ferrite nanoparticles into an electrostatic-interaction-based LbL self-assembly, we fabricated two types of films: (1) a blended three-component LbL film consisting of a sequential poly(acrylic acid)/oleic acid-ferrite blend layer and a poly(allylamine hydrochloride) layer and (2) a tetralayer LbL film consisting of sequential poly(diallyldimethylammonium chloride), poly(sodium-4-sulfonate), bPEI-ferrite, and poly(sodium-4-sulfonate) layers. We compared surface morphologies, thicknesses, and packing density of the two types of ferrite multilayer film. Ferrite nanoparticles (Co0.5Zn0.5Fe2O4) were prepared via a coprecipitation method from an aqueous precursor solution. The structure and composition of the ferrite nanoparticles were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, and scanning electron microscopy. X-ray diffraction patterns of ferrite nanoparticles indicated a cubic spinel structure, and energy dispersive X-ray spectroscopy revealed their composition. Thickness growth and surface morphology were measured using a profilometer, atomic force microscope, and scanning electron microscope.

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