Effect of Stress-induced Magnetic Anisotropy on the Properties of Giant Magnetostrictive Single Layer and Multilayer Thin Films

2004 ◽  
Vol 855 ◽  
Author(s):  
J. H. Tan ◽  
V. H. Guerrero ◽  
R. C. Wetherhold ◽  
W. A. Anderson
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Rf Sputtering ◽  
Single Layer ◽  
Annealing Treatment ◽  
Deposition Process ◽  
Vacuum System ◽  
Internal Stresses ◽  
Sensors And Actuators

ABSTRACTGiant magnetostrictive thin films deposited on nonmagnetic substrates can constitute effective sensors and actuators for microdevices. In this work, we investigated the effects of a stress-induced anisotropy on the magnetic properties of Tb0.4Fe0.6, Fe0.5Co0.5 single layer films and [Tb0.4Fe0.6/Fe0.5Co0.5]n multilayers deposited on Si substrates. The magnetostrictive thin films were fabricated by means of RF sputtering and were subjected to a post-deposition annealing treatment. The uniaxial magnetic anisotropy was induced by bending the substrate before deposition and then allowing it to resume its original flat shape after depositing the film. The heat treatment was performed in a vacuum system with a vacuum of 10−6 Torr. The magnetic properties of the fabricated specimens were measured using a SQUID. SEM and XRD analyses were performed to ensure that the thermal treatment would relax the internal stresses induced during the deposition process without crystallizing the film. The thickness of the single layer thin films studied was between 300 and 800 nm while multilayer samples consisted of 6 layers with each layer thickness ranged from about 20 to 40 nm. Compared to single layer samples, multilayer samples with stress anneal growth exhibited an improvement in magnetic saturation by a factor of two while maintaining a low coercive field. Manipulations of the magnitude and direction of magnetic anisotropy was observed by introducing various values of tensile and compressive stress into the film.

Magnetic Properties of Co-B Nanostructures Prepared via Electroless Deposition

2015 ◽  
Vol 233-234 ◽  
pp. 648-652
Author(s):  
David Richardson ◽  
Fernando M.F. Rhen
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Electroless Deposition ◽  
Deposition Time ◽  
Magnetic Measurements ◽  
Deposition Process ◽  
Specific Magnetization

We have investigated the magnetic properties of nanostructured Co-B alloys, that were prepared via electroless deposition. The deposition process results in the formation of a nanostructure consisting of nanotubes connected to thin films at both ends. Depending on the deposition time end-open or end-closed nanotubes can be formed. The overall nanostructure of Co-B deposit has a specific magnetization of 65.6 ± 8 JT-1Kg-1 (0.75 ± 0.09 μB per Co atom). We also investigated the anisotropy of the nanostructure by carrying out magnetic measurements with and without the top and base films. We only observed magnetic anisotropy in nanostructures with thin films, which had minimum coercivities of 557 A/m (7 Oe) and 4536 A/m (57 Oe) measured parallel and perpendicular to the nanotube axis. The nanotubes do not show any significant anisotropy with coercivities of 8753 A/m (110 Oe) and 7161 A/m (90 Oe) parallel and perpendicular to the nanotube axis.

Effect of Thickness on Mechanically Tunable Magnetic Anisotropy of FeGa Thin Films Deposited on Flexible Substrates

2015 ◽  
Vol 815 ◽  
pp. 227-232 ◽  
Author(s):  
Ying Yu ◽  
Shu Hong Xie ◽  
Qing Feng Zhan
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Effective Strain ◽  
Anisotropy Field ◽  
Saturation Field ◽  
Effective Anisotropy ◽  
Magnetostriction Constant ◽  
The Difference ◽  
Different Strains

A practical way to manipulate the magnetic anisotropy of magnetostrictive FeGa thin films grown on flexible polyethylene terephthalate (PET) substrates is introduced in this study. The effect of film thickness on magnetic properties and magnetostriction constant of polycrystalline FeGa thin films was investigated. The anisotropy field Hk of flexible FeGa films, i.e., the saturation field determined by fitting the hysteresis curves measured along the hard axis, was enhanced with increasing the tensile strain applied along the easy axis of the thin films, but this enhancement via strain became unconspicuous with increasing the thickness of FeGa films. In order to study the magnetic sensitivity of thin films responding to the external stress, we applied different strains on these films and measure the corresponding anisotropy field. Moreover, the effective magnetostriction constant of FeGa films was calculated from the changes of both anisotropy field and external strain based on the Villari effect. A Neel’s phenomenological model was developed to illustrate that the effective anisotropy field of FeGa thin films was contributed from both the constant volume term and the inverse thickness dependent surface term. Therefore, the magnetic properties for the volume and surface of FeGa thin films were different, which has been verified in this work by using vibrating sample magnetometer (VSM) and magneto-optic Kerr effect (MOKE) system. The anisotropy field contributed by the surface of FeGa film and obtained by MOKE is smaller than that contributed by the film volume and measured by VSM. We ascribed the difference in Hk to the relaxation of the effective strain applied on the films with increasing the thickness of films.

The Control Of Intrinsic Stresses In Cvd Diamond Films With Multistep Processing

1995 ◽  
Vol 416 ◽  
Author(s):  
S. Nijhawan ◽  
S. M. Jankovsky ◽  
B. W. Sheldon
Keyword(s):  
Thermal Stresses ◽  
Microwave Plasma ◽  
Diamond Films ◽  
Annealing Treatment ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Internal Stresses ◽  
Tensile Stresses ◽  
Si Substrates

ABSTRACTThe role of intrinsic stresses in diamond films is examined. The films were deposited on (100) Si substrates by microwave plasma-enhanced chemical vapor deposition. The total internal stresses (thermal and intrinsic) were measured at room temperature with the bending plate method. The thermal stresses are compressive and arise due to the mismatch in thermal expansion coefficient of film and substrate. The intinsic stresses were tensile and evolved during the deposition process. These stresses increased with increasing deposition time. A 12 hour intermediate annealing treatment was found to reduce the tensile stresses considerably. The annealing treatment is most effective when the diamond crystallites are undergoing impingement and coalescence. This is consistent with the theory that the maximum tensile stresses are associated with grain boundary energetics.

Influence of Platinum Bottom Electrodes on the Piezoelectric Performance of PZT Thin Films Hot Sputtered in a High Volume Production Tool

2012 ◽  
Vol 1397 ◽  
Author(s):  
Dirk Kaden ◽  
Hans-Joachim Quenzer ◽  
Martin Kratzer ◽  
Lorenzo Castaldi ◽  
Bernhard Wagner ◽  
...  
Keyword(s):  
Thin Films ◽  
Volume Fraction ◽  
Perovskite Phase ◽  
Annealing Treatment ◽  
High Volume ◽  
Deposition Process ◽  
Pzt Thin Films ◽  
Pzt Films ◽  
High Volume Production ◽  
Volume Production

ABSTRACTIn this work high quality ferroelectric PZT films have been prepared in-situ by hot RF magnetron sputtering. 200 mm wafer were coated with PZT films of 1 μm and 2 μm thickness at sputter rates of 45 nm/min in a high volume production sputtering tool. The films were grown on oxidized Si substrates prepared either with sputtered Ti/TiO2/Pt, sputtered Ti/TiO2/Pt/TiO2 or evaporated Ti/Pt bottom electrodes at substrate holder temperatures in the range from 550 °C to 700 °C. At these temperatures, the material nucleates in the requisite piezoelectric perovskite phase without need of an additional post annealing treatment.The films were investigated with respect to their chemical composition and their crystallographic, piezoelectric and dielectric properties. At an intermediate chuck temperature of 600 °C the PZT thin films were characterized by a minimum volume fraction of secondary nonpiezoelectric phases. A Zr/(Zr+Ti) ratio of 0.53 has been achieved matching the morphotropic phase boundary. By improving the deposition process and poling procedure, a notable high e31,f coefficient of -17.3 C/m2 has been obtained. The corresponding longitudinal piezoelectric constant was determined to have an effective longitudinal piezoelectric coefficient d33,f of 160 pm/V.

Influence of Stoichiometric Variations and Rapid Thermal Processing of β-FESI2 thin Films on their Electrical and Microstructural Properties

1995 ◽  
Vol 402 ◽  
Author(s):  
M. Döscher ◽  
B. Selle ◽  
M. Pauli ◽  
F. Kothe ◽  
J. Szymanski ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Beam ◽  
Thermal Processing ◽  
Rapid Thermal Processing ◽  
Rf Sputtering ◽  
Deposition Process ◽  
Silicon Substrates ◽  
Phonon Spectra ◽  
First Results

AbstractAmorphous irondisilicide thin films were deposited on silicon substrates in a RF sputtering process, followed by rapid thermal crystallization by means of moving the thin film beneath a line-shaped electron beam to form β-FeSi2. Depending on the deposition process parameters, films of a different stoichiometry can be produced. The deviations from the 1:2 stoichiometry, which have been determined by Rutherford Backscattering (RBS), are related to changes in the microstructure (studied by microscopic methods like TEM and AFM), the infrared phonon spectra (measured by FTIR spectroscopy) and the electrical properties of the crystallized films. The microstructure of the iron disilicide thin films is improved when the composition significantly deviates from 2.0, probably due to silicon interstitials in the silicide thin film. Films of different stoichiometry result in p- or n-type thin films with carrier densities below 5×1018cm−3 and hall mobilities up to 180cm 2/Vs. First results show that not only β-FeSi2-siliconheterojunctions as reported before but also pn-β-FeSi2-homojunctions show rectifying behavior. Rapid thermal processing with the line electron beam leads to a further improvement of the film quality when the scan velocity is increased up to the order of several cm/s.

ELECTRONIC STRUCTURES AND REORIENTATION OF PERPENDICULAR MAGNETIC ANISOTROPY OF Co/Au(111) and Co/Pd(111)

2002 ◽  
Vol 09 (02) ◽  
pp. 865-869
Author(s):  
M. SAWADA ◽  
K. HAYASHI ◽  
A. KAKIZAKI
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Binding Energy ◽  
Film Thickness ◽  
Magnetic Anisotropy ◽  
Photoelectron Spectroscopy ◽  
Electronic Structures ◽  
Perpendicular Magnetic Anisotropy ◽  
Magnetization Direction ◽  
Electronic And Magnetic Properties

We have investigated electronic and magnetic properties of Co thin films epitaxially grown on Au(111) and Pd(111) substrates by spin- and angle-resolved photoelectron spectroscopy. In the Co/Au(111) system, the magnetization direction of Co changes from perpendicular to parallel to the surface at about 6 ML. The origin of the reorientation is qualitatively explained by the increasing contribution of Co 3d orbitals perpendicular to the surface. In the Co/Pd(111) system, the reorientation of the magnetization direction occurs at about 4 ML, the origin of which is explained as being due to the contribution of the upper Λ3 band of Co with increase of film thickness as in the case of the Co/Au(111) system. The stronger hybridization between Co 3d and Pd 4d states in the Co/Pd(111) system causes larger binding energy shifts of the Λ3 states than in the Co/Au(111) system.

scholarly journals Effects of Substrate Temperature and Annealing Treatment on the Magnetic Properties of Giant-Magnetostrictive (Tb,Dy)Fe2 Thin Films.

1993 ◽  
Vol 5 (4) ◽  
pp. 116
Author(s):  
Mitsuhiro WADA ◽  
Atsushi YAMAMOTO ◽  
Akiko ICHIKAWA ◽  
Masanori TAKI ◽  
Masaru UCHIYAMA ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Substrate Temperature ◽  
Annealing Treatment
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