scholarly journals Effect of Annealing on the Structural, Magnetic and Surface Energy of CoFeBY Films on Si (100) Substrate

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 987
Author(s):  
Wen-Jen Liu ◽  
Yung-Huang Chang ◽  
Yuan-Tsung Chen ◽  
Yi-Chen Chiang ◽  
Yu-Chi Liu ◽  
...  

The structure, magnetic properties, optical properties and adhesion efficiency of CoFeBY films were studied. Co40Fe40B10Y10 alloy was sputtered onto Si (100) with a thickness of 10–50 nm, and then annealed at room temperature, 100 °C, 200 °C and 300 °C for 1 h. X-ray diffraction (XRD) showed that the CoFeBY films deposited at room temperature are amorphous. Annealing at 100 °C gave the films enough thermal energy to change the structure from amorphous to crystalline. After annealing, the CoFeBY thin film showed a body-centered cubic (BCC) CoFeB (110) characteristic peak at 44°. However, the low-frequency alternative-current magnetic susceptibility (χac) and saturation magnetization (MS) increased with the increase of thickness. CoFeBY thin films had the highest χac and MS after annealing at 300 °C compared to that at other temperatures. After annealing at 300 °C, the surface energy of CoFeBY film is the maximum at 50 nm. Higher surface energy indicated stronger adhesion.

2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
S. K. Wang ◽  
Yuan-Tsung Chen ◽  
S. R. Jian

This study examined the deposition of CoFeB thin films on a glass substrate at room temperature (RT), as well as the effects of conducting postannealing at heat annealingTA=150°C for 1 h. The thickness (tf) of the CoFeB thin films ranged from 100 Å to 500 Å. The microstructure, average contact angle, and surface energy properties were also investigated. X-ray diffraction (XRD) revealed that CoFeB films are nanocrystalline at RT and that post-annealing treatment increases in conjunction with the crystallinity. The surface energy of the CoFeB thin films is related to adhesive strength. The CoFeB films form a contact angle of larger than90∘with water as a test liquid. This finding demonstrates that the CoFeB film is hydrophobic. Astfincreases from 100 Å to 500 Å, the surface energy at RT decreases from 40 mJ/mm2to 32 mJ/mm2. During post-annealing treatment, the surface energy increases from 32 mJ/mm2to 35 mJ/mm2, astfincreases from 100 Å to 300 Å; then it decreases to 31 mJ/mm2, astfincreases from 300 Å to 500 Å. The surface energy of the as-deposited CoFeB thin films exceeds that during post-annealing treatment at thicknesses of 100 Å and 200 Å, suggesting that as-deposited CoFeB thin film increases the adhesion.


2013 ◽  
Vol 710 ◽  
pp. 170-173
Author(s):  
Lian Ping Chen ◽  
Yuan Hong Gao

It is hardly possible to obtain rare earth doped CaWO4thin films directly through electrochemical techniques. A two-step method has been proposed to synthesize CaWO4:(Eu3+,Tb3+) thin films at room temperature. X-ray diffraction, energy dispersive X-ray analysis, spectrophotometer were used to characterize their phase, composition and luminescent properties. Results reveal that (Eu3+,Tb3+)-doped CaWO4films have a tetragonal phase. When the ratio of n (Eu)/n (Tb) in the solution is up to 3:1, CaWO4:(Eu3+,Tb3+) thin film will be enriched with Tb element; on the contrary, when the ratio in the solution is lower than 1:4, CaWO4:(Eu3+,Tb3+) thin film will be enriched with Eu element. Under the excitation of 242 nm, sharp emission peaks at 612, 543, 489 and 589 nm have been observed for CaWO4:(Eu3+,Tb3+) thin films.


2005 ◽  
Vol 879 ◽  
Author(s):  
M. Abid ◽  
C. Terrier ◽  
J-P Ansermet ◽  
K. Hjort

AbstractFollowing the theory, ferromagnetism is predicted in Mn- doped ZnO, Indeed, ferromagnetism above room temperature was recently reported in thin films as well as in bulk samples made of this material. Here, we have prepared Mn doped ZnO by electrodeposition. The samples have been characterized by X-ray diffraction and spectroscopic methods to ensure that the dopants are substitutional. Some samples exhibit weak ferromagnetic properties at room temperature, however to be useful for spintronics this material need additional carriers provided by others means.


Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 91 ◽  
Author(s):  
Chunping Xu ◽  
Wenjun Wang

Helium (He) effect on the microstructure of nanocrystalline body-centered cubic iron (BCC-Fe) was studied through Molecular Dynamics (MD) simulation and simulated X-ray Diffraction (XRD). The crack generation and the change of lattice constant were investigated under a uniaxial tensile strain at room temperature to explore the roles of He concentration and distribution played in the degradation of mechanical properties. The simulation results show that the expansion of the lattice constant decreases and the swelling rate increases while the He in the BCC region diffuses into the grain boundary (GB) region. The mechanical property of nanocrystalline BCC-Fe shows He concentration and distribution dependence, and the existence of He in GB is found to benefit the generation and growth of cracks and to affect the strength of GB during loading. It is observed that the reduction of tensile stress contributed by GB He is more obvious than that contributed by grain interior He.


1999 ◽  
Vol 14 (6) ◽  
pp. 2484-2487 ◽  
Author(s):  
Seo-Yong Cho ◽  
Chang-Hun Kim ◽  
Dong-Wan Kim ◽  
Kug Sun Hong ◽  
Jong-Hee Kim

Ln(Mg1/2Ti1/2)O3 (Ln = Dy, La, Nd, Pr, Sm, Y) compositions have been prepared, and their pertinent properties for use as thin film substrates for YBa2Cu3Ox (YBCO) were measured. X-ray diffraction shows that Ln(Mg1/2Ti1/2)O3 compositions have noncubic symmetry and the GdFeO3-type structure. Dielectric constant measurements revealed values between 22 and 27, which are larger than those of the LnAlO3 family. Quality factor (=1/ tan δ) of the ceramic specimens measured at room temperature was larger than 3000 at 10 GHz. Among the compounds, La(Mg1/2Ti1/2)O3 exhibited the highest dielectric constant and the lowest dielectric loss. Chemical reaction was observed between Ln(Mg1/2Ti1/2)O3 (Ln = Dy, Sm, Y) and YBCO after annealing a 1 : 1 mixture at 950 °C. Considering dielectric and physical properties, La(Mg1/2Ti1/2)O3 and Sm(Mg1/2Ti1/2)O3 were determined to be suitable substrates for YBCO thin film used in microwave applications.


2018 ◽  
Vol 27 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Emaad T Bakir Al-Tikrity ◽  
Ibrahim F Waheed ◽  
Sabah M Ali

This work reports the synthesis and characterisation of reduced graphene-1,3,4-oxadiazole-2-thiol (rGS) as a novel nanocompound derivative for graphene. The preparation was performed through a series of reactions starting from graphene oxide, followed by incorporation of different proportions of this nanocompound with poly(vinyl alcohol) (PVA), via non-covalent bonding, to afford the rGS/PVA polymer composites. The pure rGS compound, rGS/PVA composite films and pure PVA film were characterised by different techniques including infrared (Fourier transform infrared) spectroscopy, scanning electron microscopy and powder x-ray diffraction. The electrical properties of the composite films, involving dielectric constant, permittivity ( ε′), imaginary permittivity ( ε″), conductivity (σAC) and loss factor tan δ, were investigated. The measurements were performed at frequencies of (5kHz to 0.5 MHz) at room temperature. At low frequency, the dielectric permittivity ( ε′) and imaginary permittivity ( ε″) attained higher values in all cases, although with increasing frequency these values diminished rapidly. It was also found that the alternating current conductivity of the composites increased with increasing frequency.


1999 ◽  
Vol 603 ◽  
Author(s):  
B.J. Gibbons ◽  
Y. Fan ◽  
A.T. Findikoglu ◽  
D.W. Reagor ◽  
Q.X. Jia

AbstractThe low frequency dielectric properties of epitaxial SrTiO3 thin films deposited on LaAlO3 are presented. The films were deposited using radio-frequency magnetron sputtering from stoichiometric targets in an Ar/O2 atmosphere. For the first time, the effects of in situ ozone annealing during the early stages of deposition were explored. X-ray diffraction results indicated that the ozone treatment resulted in more symmetric and sharper diffraction peaks (2 Θ- FWHM decreased from 0.17° to 0.10°). In addition, the peaks for the ozone treated samples were shifted in 2 Θ towards values approaching the bulk value. Rutherford backscattering measurements showed Sr/Ti ratios of 1:1 for these samples, indicating these peak shifts are not due to compositional variations. The dielectric constant of the ozone treated samples increased from 275 at room temperature to 1175 at 22 K (measured at 100 kHz). The effective loss tangent of the device remained between 1 × 10−4 and 1 × 10−3 down to 100 K, where it began to increase. The tunability was also measured. The ozone treated sample showed tunability of 46%, 43% and 38% at 22 K, 40 K and 60 K, respectively. Finally, similar measurements were completed at 1 MHz, indicating a minimal dependence of these properties on frequencies in this range.


2008 ◽  
Vol 15 (04) ◽  
pp. 515-518
Author(s):  
S. Y. HUANG ◽  
S. XU ◽  
J. D. LONG ◽  
J. W. CHAI ◽  
Q. J. CHENG

Cadmium sulfide ( CdS ) nanocrystals are successfully fabricated on glass and silicon substrates at room temperature with low-frequency (460 kHz) inductively coupled plasma assisted magnetron sputtering technique. Both size and shape can be controlled by changing deposition parameters and substrates. Field-emission scanning electron microscope, energy dispersive X-ray spectroscopy, and X-ray diffraction are adopted to measure the properties of CdS nanorods.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Yuan-Tsung Chen

Ta films were sputtered onto a glass substrate with thicknesses from 500 Å to 1500 Å under the following conditions: (a) as-deposited films were maintained at room temperature (RT), (b) films were postannealed atTA=150°C for 1 h, and (c) films were postannealed atTA=250°C for 1 h. X-ray diffraction (XRD) results revealed that the Ta films had a body-centered cubic (BCC) structure. Postannealing conditions and thicker Ta films exhibited a stronger Ta (110) crystallization than as-deposited and thinner films. The nanoindention results revealed that Ta thin films are sensitive to mean grain size, including a valuable hardness (H) and Young’s modulus (E). High nanomechanical properties of as-deposited and thinner films can be investigated by grain refinement, which is consistent with the Hall-Petch effect. The surface energy of as-deposited Ta films was higher than that in postannealing treatments. The adhesion of as-deposited Ta films was stronger than postannealing treatments because of crystalline degree effect. The maximalHandEand the optimal adhesion of an as-deposited 500-Å-thick Ta film were 15.6 GPa, 180 GPa, and 51.56 mJ/mm2, respectively, suggesting that a 500-Å-thick Ta thin film can be used in seed and protective layer applications.


Author(s):  
M. Reiberg ◽  
X. Li ◽  
E. Maawad ◽  
E. Werner

AbstractIn this work, multi-principal element alloys (MPEAs) with the five base elements Al, Cr, Fe, Ni and Ti plus elements in minor amounts were produced by powder metallurgy and their microstructure and elastic behavior were analyzed via light and scanning electron microscopy, electron backscatter diffraction (EBSD) and synchrotron X-ray diffraction. The two studied compositions are an MPEA with Al, Cr, Fe, Ni and Ti in equimolar ratio as well as a similar composition with a concentration of Ti reduced to 10 mol%. The goal is to analyze the microstructural behavior of these compositions during macroscopic loading in dependence of chemical composition and phases present. Analysis via synchrotron X-ray diffraction predicts the presence of body-centered cubic phases, Full Heusler-phases and C14_Laves-phases in both compositions, MPEA5 and MPEA_Ti10. Synchrotron X-ray diffraction offers the possibility to monitor the deformation of these phases during macroscopic loading of specimens. Thermodynamic calculations of stable phases predicted a microstructure of MPEA5 consisting of body-centered cubic and Full Heusler-phases at room temperature. Further calculation and X-ray diffraction experiments showed the stabilization of minor amounts of C14_Laves-phase ($$\hbox {Fe}_2\hbox {Ti}$$ Fe 2 Ti ) at room temperature with a decreasing amount of Ti. MPEA5 showed the development of long and un-branched cracks during compressive testing, which resulted in a remarkable decrease in lattice-dependent elastic moduli. MPEA_Ti10 exhibited branched cracks during compression tests. Also, the lattice-dependent elastic moduli of MPEA_Ti10 did not change notably during the compression tests. In both compositions, the Full Heusler-phase showed the lowest lattice-dependent elastic moduli, hence taking the largest share of the overall deformation among all phases present in the materials under macroscopic loading.


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