Structural and Magnetotransport Properties of NiMnSb/Cu and NiMnSb/Ag Multilayers

1997 ◽  
Vol 475 ◽  
Author(s):  
J.A. Caballero ◽  
F. Petroff ◽  
A. Cabbibo ◽  
Y.D. Park ◽  
J.R. Childress
Keyword(s):  
Layer Thickness ◽  
Thin Layers ◽  
Crystalline Quality ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Spacer Layer ◽  
Spin Polarized ◽  
The Relationship ◽  
Substrate Temperatures

ABSTRACTWe report on the integration of the predicted half-metallic (100% spin-polarized) ferromagnetic Heusler alloy NiMnSb into NiMnSb/Cu and NiMnSb/Ag multilayer structures, and on their magnetic, microstructural and magnetotransport properties. The NiMnSb layer thickness was fixed at 30Å and those of Cu and Ag were varied from 5 to 60Å. The multilayers were characterized using x-ray diffraction (XRD), four-wire resistivity measurements, atomic force microscopy, SQUID magnetometry and magnetotransport measurements. Moderate substrate temperatures (250°C) are shown to be sufficient to produce stochiometric Clb-structured NiMnSb. XRD data confirm that the NiMnSb ultra-thin layers retain their crystalline quality and texture. SQUID measurements shows that the bulk saturation magnetization (∼740 emu/cm3) is maintained and that it is strongly sensitive to interlayer diffusion and roughness. AFM studies show that the surface roughness, which can be as low as 4Å, depends on the choice of spacer layer, layer thickness and substrate temperature. The relationship between the measured magnetoresistance, NiMnSb crystalline quality, magnetic properties and interfacial roughness are discussed.

scholarly journals Isotropic microscale mechanical properties of coral skeletons

2015 ◽  
Vol 12 (106) ◽  
pp. 20150168 ◽  
Author(s):  
Luca Pasquini ◽  
Alan Molinari ◽  
Paola Fantazzini ◽  
Yannicke Dauphen ◽  
Jean-Pierre Cuif ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Nacreous Layer ◽  
X Ray Diffraction ◽  
Stylophora Pistillata ◽  
Force Microscopy ◽  
Coral Skeletons ◽  
Atomic Force ◽  
Diffraction Patterns ◽  
The Relationship ◽  
Atrina Rigida

Scleractinian corals are a major source of biogenic calcium carbonate, yet the relationship between their skeletal microstructure and mechanical properties has been scarcely studied. In this work, the skeletons of two coral species: solitary Balanophyllia europaea and colonial Stylophora pistillata , were investigated by nanoindentation. The hardness H IT and Young's modulus E IT were determined from the analysis of several load–depth data on two perpendicular sections of the skeletons: longitudinal (parallel to the main growth axis) and transverse. Within the experimental and statistical uncertainty, the average values of the mechanical parameters are independent on the section's orientation. The hydration state of the skeletons did not affect the mechanical properties. The measured values, E IT in the 76–77 GPa range, and H IT in the 4.9–5.1 GPa range, are close to the ones expected for polycrystalline pure aragonite. Notably, a small difference in H IT is observed between the species. Different from corals, single-crystal aragonite and the nacreous layer of the seashell Atrina rigida exhibit clearly orientation-dependent mechanical properties. The homogeneous and isotropic mechanical behaviour of the coral skeletons at the microscale is correlated with the microstructure, observed by electron microscopy and atomic force microscopy, and with the X-ray diffraction patterns of the longitudinal and transverse sections.

Morphology and orientation of thin poly(3-hexylthiophene) (P3HT) films on differently silanized silicon oxide

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Guido Scavia ◽  
William Porzio ◽  
Silvia Destri ◽  
Alberto Giacometti Schieroni ◽  
Fabio Bertini
Keyword(s):  
Annealing Temperature ◽  
Silicon Oxide ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Thin Layers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Xrd Techniques

AbstractThe morphology and structure of the overlying poly(3-hexylthiophene) (P3HT) layer onto differently silanized silicon oxide has been studied by Atomic Force Microscopy (AFM) and X-Ray Diffraction (XRD) techniques. By increasing the silanizer alkyl chain length, the layer morphology evolves from a filament like to globular needle like as a consequence of the different SAM organization, while the P3HT conformation remains edge-on. For each case the effect of the annealing temperature has been studied. For all the cases a particular attention has been paid to the first thin layers close to the interface P3HT/SiOx. The effect of a polar substituent and presence of aromatic ring has been also studied.

Investigation of Structural and Mechanical Properties of Laser Deposited Microlaminate Hard Coatings

2001 ◽  
Vol 697 ◽  
Author(s):  
Manoj Radder ◽  
A.K. Sikder ◽  
Ashok Kumar
Keyword(s):  
Mechanical Properties ◽  
Boron Carbide ◽  
Composite Coatings ◽  
Bottom Layer ◽  
Hard Coatings ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Substrate Temperatures

Nitride and carbide are superhard material with a high potential for applications in different fields. A new group of coatings are the multilayered/microlaminate coatings, which have shown very interesting properties. Single and microlaminate films were coated on Silicon (Si) substrates using pulsed laser deposition (PLD) technique. Films were deposited at different substrate temperatures in order to study the microstructure evolution and their effect on the mechanical properties of these microlaminate films. Structure of the films was characterized by x-ray diffraction (XRD) technique. Surface morphology and roughness of the films were investigated using atomic force microscopy (AFM). Hardness and modulus of the films were investigated using nanoindentation technique. It has been demonstrated that using boron carbide as a bottom layer increases the hardness and Young's modulus values of carbide composite coatings. Microlaminates of boron carbide/titanium carbides have shown higher hardness and modulus as compared to the microlaminates of nitride coatings.

Fabrication of A Barium Titanate-Strontium Titanate Strained Layer Superlattice

1995 ◽  
Vol 397 ◽  
Author(s):  
S.D. Harkness ◽  
R.K. Singh
Keyword(s):  
Critical Thickness ◽  
Laser Deposition ◽  
Processing Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Order Of Magnitude ◽  
Strained Layer Superlattice ◽  
Substrate Temperatures

ABSTRACTA thin film superlattice heterostructure composed of alternating BaTiO3 and SrTiO3 layers was grown on a thin YBa2Cu3O7 electrode templated on a (100) SrTiO3 wafer using the pulsed laser deposition method. Stranski-Krastanov nucleation of the layers was demonstrated using atomic force microscopy (AFM) when processing conditions were maintained at 6 millitorr oxygen partial pressure, and 550 °C substrate temperatures. High-resloution x-ray diffraction (HRXRD) measurements indicate that all the deformation was concentrated in the BaTiO3 layers with c/a extension to approximately 1.08. Rutherford backscattering spectroscopy (RBS) results indicate excellent crystallinity in the heterostructure. The microstructural data suggests that the theoretical critical thickness of the film has been surpassed by an order of magnitude.

SURFACE MORPHOLOGY AND PHOTOLUMINESCENCE CHARACTERISTICS OF Sm-DOPED YVO4 THIN FILMS

2007 ◽  
Vol 14 (05) ◽  
pp. 873-878 ◽  
Author(s):  
HYUN KYOUNG YANG ◽  
JONG WON CHUNG ◽  
BYUNG KEE MOON ◽  
BYUNG CHUN CHOI ◽  
JUNG HYUN JUNG ◽  
...  
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Substrate Temperature ◽  
Photoluminescence Intensity ◽  
Photoluminescence Spectra ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Zircon Structure ◽  
Substrate Temperatures

Surface morphology and crystallinity of YVO 4: Sm 3+ thin films have an influence on the photoluminescence characteristics. The YVO 4: Sm 3+ films have been deposited on Al 2 O 3 (0001) substrates using pulsed laser deposition method. The films were grown at the various substrate temperatures changing from 500 to 700°C. The crystallinity and surface morphology of the films were investigated using X-ray diffraction (XRD) and atomic force microscopy (AFM), respectively. The results of XRD showed that YVO 4: Sm 3+ films had a zircon structure and AFM study revealed that the films consisted of homogeneous grains ranging from 100 to 400 nm depending on the deposition conditions. The photoluminescence spectra were measured at room temperature and the emitted radiation was dominated by the red emission peak at 620 nm radiated from the transition of 5 D 0-7 F 2. The crystallinity, surface morphology, and photoluminescence spectra of thin-film phosphors were highly dependent on the substrate temperature. The surface roughness and photoluminescence intensity of the films showed similar behavior as a function of substrate temperature.

GaZnO as a Transparent Electrode to Silicon Carbide

2012 ◽  
Vol 717-720 ◽  
pp. 849-852
Author(s):  
Jung Ho Lee ◽  
Ji Hong Kim ◽  
Kang Min Do ◽  
Byung Moo Moon ◽  
Sung Jae Joo ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Hall Effect Measurement ◽  
Transparent Electrode ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Structural And Electrical Properties ◽  
Substrate Temperature Increase ◽  
Substrate Temperatures

The characteristics of Ga-doped zinc oxide (GaZnO) thin films deposited at different substrate temperatures (TS~250 to 550oC) on 4H-SiC have been investigated. Structural and electrical properties of GaZnO thin film on n-type 4H-SiC (100)were investigated by using x-ray diffraction, atomic force microscopy (AFM), Hall effect measurement, and Auger electron spectroscopy (AES). Hall mobility is found to increase as the substrate temperature increase from 250 to 550 oC, whereas the lowest resistivity (~3.3 x 10-4 Ωcm) and highest carrier concentration (~1.33x1021cm-3) values are observed for the GaZnO films deposited at 400 oC. It has been found that the c-axis oriented crystalline quality as well as the relative amount of activated Ga3+ Introduction ions may affect the electrical properties of GaZnO films on SiC.

Preparation of Cu(In,Ga)Se2 thin films at low substrate temperatures

2001 ◽  
Vol 16 (2) ◽  
pp. 394-399 ◽  
Author(s):  
S. Nishiwaki ◽  
T. Satoh ◽  
Y. Hashimoto ◽  
T. Negami ◽  
T. Wada
Keyword(s):  
Thin Films ◽  
Surface Composition ◽  
Soda Lime ◽  
Soda Lime Glass ◽  
X Ray Diffraction ◽  
Monitoring Method ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Substrate Temperatures

Cu(In,Ga)Se2(CIGS) thin films were prepared at substrate temperatures of 350 to 500 °C. The (In,Ga)2Se2 precursor layers were deposited on Mo coated soda-lime glass and then exposed to Cu and Se fluxes to form CIGS films. The surface composition was probed by a real-time composition monitoring method. The CIGS films were characterized by x-ray diffraction, energy dispersive x-ray spectroscopy, secondary ion mass spectroscopy, and atomic force microscopy. The transient formation of a Cu–Se phase with a high thermal emissivity was observed during the deposition of Cu and Se at a substrate temperature of 350 °C. Faster diffusion of In than Ga from the (In,Ga)2Se3 precursor to the newly formed CIGS layer was observed. A growth model for CIGS films during the deposition of Cu and Se onto (In,Ga)2Se3 precursor is proposed. A solar cell using a CIGS film prepared at about 350 °C showed an efficiency of 12.4%.

Heteroepitaxial Growth of Epitaxial C60-Thin Films on Mica(001)

1994 ◽  
Vol 359 ◽  
Author(s):  
S. Henke ◽  
K.H. Thürer ◽  
S. Geier ◽  
B. Rauschenbach ◽  
B. Stritzker
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Substrate Temperature ◽  
Room Temperature ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Substrate Temperatures

ABSTRACTOn mica(001) thin C60-films are deposited by thermal evaporation at substrate temperatures from room temperature up to 225°C. The dependence of the structure and the epitaxial alignment of the thin C60-films on mica(001) on the substrate temperature and the film thickness up to 1.3 μm at a well-defined deposition rate (0.008 nm/s) is investigated by atomic force microscopy and X-ray diffraction. The shape and the size of the C60-islands, which have an influence on the film quality at larger film thicknesses, are sensitively dependent on the substrate temperature. At a film thickness of 200 nm the increase of the substrate temperature up to 225°C leads to smooth, completely coalesced epitaxial C60-thin films characterized by a roughness smaller than 1.5 nm, a mosaic spread Δω of 0.1° and an azimuthal alignment ΔΦ of 0.45°.

Pulsed Laser Deposition of Tungsten Thin Films on Graphite

2011 ◽  
Vol 324 ◽  
pp. 77-80 ◽  
Author(s):  
Wassim Kassem ◽  
Malek Tabbal ◽  
Mohamad Roumie
Keyword(s):  
Substrate Temperature ◽  
Laser Fluence ◽  
Thin Layers ◽  
X Ray Diffraction ◽  
Rutherford Back Scattering ◽  
Force Microscopy ◽  
Atomic Force ◽  
Back Scattering ◽  
Krf Excimer Laser ◽  
Background Gas

Thin coatings of Tungsten were deposited on substrates fabricated by pre-depositing graphite thin layers on Si(100) wafers. We ablate pure W target using a 20 ns KrF excimer laser (248 nm) in an Ar ambient. The effect of background gas pressure, substrate temperature, and laser fluence, on the properties of the deposited W layers is studied using several techniques including X-Ray Diffraction, Atomic Force Microscopy, surface profilometry, and Rutherford Back-Scattering spectrometry. Our results indicate that the deposited layers consist of the well-crystallized body-centered-cubic α-W phase with bulk-like properties, particularly for films deposited at a substrate temperature of 450°C, laser fluence greater than 400mJ, and pressure of about 10mTorr.

Structural Study of Tailored Titania Thin Layers

2008 ◽  
Vol 73 (8-9) ◽  
pp. 1222-1230 ◽  
Author(s):  
Olga Šolcová ◽  
Lenka Matějová ◽  
Simona Krejčíková ◽  
Zdeněk Matěj ◽  
Radomír Kužel ◽  
...  
Keyword(s):  
Physical Adsorption ◽  
Dip Coating ◽  
Thin Layers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Air Stream ◽  
Titania Layer ◽  
Structure Properties

Thin nanolayers of titania prepared by repeated dip-coating of silica glass into a transparent homogeneous sol made from nonionic surfactants with various numbers of oxyethylene units were studied. Calcination in air stream was used to convert transparent gel layers into anatase layers. The surface morphology, roughness, structure and texture properties were estimated by nitrogen physical adsorption, X-ray diffraction characterization, atomic force microscopy, transmission and scanning electron microscopy. Additionally, the contact angle determination was tested as a rapid method for evaluation of the titania layer surface quality. The influence of the number of oxyethylene units in surfactants on texture and structure properties of the prepared titania layers was found and discussed.

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