Effect of Sputtering Input Power of Co on Structure and Magnetic Properties of Fe-Co-N Thin Films

2009 ◽  
Vol 79-82 ◽  
pp. 635-638 ◽  
Author(s):  
Xin Wang ◽  
Hui Jia ◽  
Wei Tao Zheng ◽  
Wei Xu ◽  
Bei Hong Long

Fe-Co-N thin films with various Co content were synthesized on Si (111) substrate using facing-target magnetron sputtering by changing sputtering input power on Co target. During deposition, the input power on Fe target was kept at 160 W. The composition, structure, and magnetic properties were examined by X-ray photoelectron spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and superconducting quantum interference device. XRD and TEM investigations showed that at lower input power of 11.2 W on Co target, the phases in the film were -(Fe,Co)4N and Co3N. Increasing sputtering input power, the content of Co in the film increased. At input power of 14 W, film contained -(Fe,Co)8N phase was produced which exhibited higher saturation magnetization (252.85 Am2/kg) and lower value of coercivity (3.66 kAm-1), corresponded to the 12% content of Co in the film.

1998 ◽  
Vol 533 ◽  
Author(s):  
Glenn G. Jernigan ◽  
Conrad L. Silvestre ◽  
Mohammad Fatemi ◽  
Mark E. Twigg ◽  
Phillip E. Thompson

AbstractThe use of Sb as a surfactant in suppressing Ge segregation during SiGe alloy growth was investigated as a function of Sb surface coverage, Ge alloy concentration, and alloy thickness using xray photoelectron spectroscopy, x-ray diffraction, and transmission electron microscopy. Unlike previous studies where Sb was found to completely quench Ge segregation into a Si capping layer, we find that Sb can not completely prevent Ge segregation while Si and Ge are being co-deposited. This results in the production of a non-square quantum well with missing Ge at the beginning and extra Ge at the end of the alloy. We also found that Sb does not relieve strain in thin films but does result in compositional or strain variations within thick alloy layers.


2010 ◽  
Vol 177 ◽  
pp. 32-36 ◽  
Author(s):  
An Rong Wang ◽  
Jian Li ◽  
Qing Mei Zhang ◽  
Hua Miao

Weak magnetic ZnFe2O4 nanoparticles were prepared by coprecipitation and treated with different concentrations of Fe(NO3)3 solution. Untreated and treated particles were studied using a vibrating sample magnetometer, transmission electron microscope, by X-ray diffraction, X-ray energy dispersive spectroscopy and X photoelectron spectroscopy. The results showed that, after treatment, the ZnFe2O4/γ-Fe2O3 forms disphase nanoparticles, with enlarged size, enhanced magnetic properties and with a surface parceled with Fe(NO3)3. The size of the particles and their magnetic properties are related to the concentration of the treatment solution. The particle size and magnetic properties could be controlled by controlling the concentration of treating solution, therefore nanoparticles can be more widely used.


2013 ◽  
Vol 275-277 ◽  
pp. 1952-1955
Author(s):  
Ling Fang Jin ◽  
Xing Zhong Li

New functional nanocomposite FePt:C thin films with FePt underlayers were synthesized by noneptaxial growth. The effect of the FePt layer on the ordering, orientation and magnetic properties of the composite layer has been investigated by adjusting FePt underlayer thickness from 2 nm to 14 nm. Transmission electron microscopy (TEM), together with x-ray diffraction (XRD), has been used to check the growth of the double-layered films and to study the microstructure, including the grain size, shape, orientation and distribution. XRD scans reveal that the orientation of the films was dependent on FePt underlayer thickness. In this paper, the TEM studies of both single-layered nonepitaxially grown FePt and FePt:C composite L10 phase and double-layered deposition FePt:C/FePt are presented.


2013 ◽  
Vol 313-314 ◽  
pp. 254-257
Author(s):  
Ling Fang Jin ◽  
Hong Zhuang

Nonepitaxially grown FePt (x)/FePt:C thin films were synthesized, where FePt (x) (x=2, 5, 8, 11, 14 nm) layers were served as underlayers and FePt:C layer was nanocomposite with thickness of 5 nm. The effect of FePt underlayer on the ordering, orientation and magnetic properties of FePt:C thin films has been investigated by adjusting FePt underlayer thicknesses from 2 nm to 14 nm. X-ray diffraction (XRD), together with transmission electron microscopy (TEM) confirmed that the desired L10 phase was formed and films were (001) textured with FePt underlayer thickness decreased less 5 nm. For 5 nm FePt:C nanocomposite thin film with 2 nm FePt underlayer, the coercivity was 8.2 KOe and the correlation length of FePt:C nanocomposite film was 67 nm. These results reveal that the better orientation and magnetic properties for FePt:C nanocomposite films can be tuned by decreasing FePt underlayer thickness.


2013 ◽  
Vol 385-386 ◽  
pp. 7-10
Author(s):  
Ling Fang Jin ◽  
Hong Zhuang

Nonepitaxially grown double-layered films were synthesized with a FePt: C composite layer on top of continuous FePt underlayer. The thickness of FePt was changed from 2 nm to 14 nm. Nanostructures, crystalline orientations and the effect of FePt underlayer on the ordering, orientation and magnetic properties of the thin films were investigated by transmission electron microscopy (TEM) and x-ray diffraction (XRD). XRD confirmed the formation of the ordered L10phase for 5 nm FePt: C film with FePt thickness decreased to 5 nm. TEM studies of FePt:C composite L10phase and double-layered deposition FePt:C/FePt were presented.


2009 ◽  
Vol 24 (8) ◽  
pp. 2483-2498 ◽  
Author(s):  
Axel Flink ◽  
Manfred Beckers ◽  
Jacob Sjölén ◽  
Tommy Larsson ◽  
Slawomir Braun ◽  
...  

(Ti1–xSix)Ny (0 ≤ x ≤ 0.20; 0.99 ≤ y(x) ≤ 1.13) thin films deposited by arc evaporation have been investigated by analytical transmission electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy, and nanoindentation. Films with x ≤ 0.09 are single-phase cubic (Ti,Si)N solid solutions with a dense columnar microstructure. Films with x > 0.09 have a featherlike microstructure consisting of cubic TiN:Si nanocrystallite bundles separated by metastable SiNz with coherent-to-semicoherent interfaces and a dislocation density of as much as 1014 cm−2 is present. The films exhibit retained composition and hardness between 31 and 42 GPa in annealing experiments to 1000 °C due to segregation of SiNz to the grain boundaries. During annealing at 1100–1200 °C, this tissue phase thickens and transforms to amorphous SiNz. At the same time, Si and N diffuse out of the films via the grain boundaries and TiN recrystallize.


2003 ◽  
Vol 789 ◽  
Author(s):  
A. Goodarzi ◽  
Y. Sahoo ◽  
M. T. Swihart ◽  
P. N. Prasad

ABSTRACTMagnetic nanoparticles have found application in medical diagnostics such as magnetic resonance imaging and therapies such as cancer treatment. In these applications, it is imperative to have a biocompatible solvent such as water at optimum pH for possible bio-ingestion. In the present work, a synthetic methodology has been developed to get a well-dispersed and homogeneous aqueous suspension of Fe3O4 nanoparticles in the size range of 8–10 nm. The surface functionalization of the particles is provided by citric acid. The particles have been characterized using transmission electron microscopy, magnetization measurements with a superconducting quantum interference device, FTIR spectroscopy (for surfactant binding sites), thermogravimetric studies (for strength of surfactant binding), and x-ray photoelectron spectroscopy and x-ray diffraction (for composition and phase information). The carboxylate functionality on the surface provides an avenue for further surface modification with fluorescent dyes, hormone linkers etc for possible cell-binding, bioimaging, tracking, and targeting.


2004 ◽  
Vol 19 (4) ◽  
pp. 352-355 ◽  
Author(s):  
Wei Tao Zheng ◽  
Xin Wang ◽  
Xianggui Kong ◽  
Hongwei Tian ◽  
Shansheng Yu ◽  
...  

Fe–N thin films were deposited on glass substrates by dc magnetron sputtering under various Ar∕N2 discharge conditions. Crystal structures and elemental compositions of the films were characterized by X-ray diffraction and X-ray photoelectron spectroscopy. Magnetic properties of the films were measured using a superconducting quantum interference device magnetometer. Films deposited at different N2∕(Ar+N2) flow ratios were found to have different crystal structures and different nitrogen contents. When the flow ratios were 60%, 50%, and 30%, a nonmagnetic single-phase FeN was formed in the films. At the flow ratio of 10%, two crystal phases of γ′-Fe4N and ε-Fe3N were detected. When the flow ratio reduced to 5%, a mixture of α-Fe, ε-Fe3N, FeN0.056, and α″-Fe16N2 phases was obtained. The value of saturation magnetization for the mixture was found to be larger than that of pure Fe.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Jude Namanga ◽  
Josepha Foba ◽  
Derek Tantoh Ndinteh ◽  
Divine Mbom Yufanyi ◽  
Rui Werner Maçedo Krause

Magnetic nanocomposites composed of superparamagnetic magnetite nanoparticles in a pectin matrix were synthesized by an in situ coprecipitation method. The pectin matrix acted as a stabilizer and size control host for the magnetite nanoparticles (MNPs) ensuring particle size homogeneity. The effects of the different reactant ratios and nanocomposite drying conditions on the magnetic properties were investigated. The nanocomposites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared (FT-IR) spectroscopy, and superconducting quantum interference device magnetometer (SQUID). Superparamagnetic magnetite nanoparticles with mean diameters of 9 and 13 nm were obtained, and the freeze-dried nanocomposites had a saturation magnetization of 54 and 53 emu/g, respectively.


2002 ◽  
Vol 17 (12) ◽  
pp. 3163-3167 ◽  
Author(s):  
Jose L. Endrino ◽  
James E. Krzanowski

The mechanical properties of WC–SiC thin films deposited by dual radio frequency magnetron sputtering were investigated. The films were characterized by x-ray photoelectron spectroscopy, x-ray diffraction (XRD), and transmission electron microscopy (TEM) to evaluate the details of the microstructure and degree of amorphization. The results indicate that small additions of SiC (<25%) can significantly increase hardness compared to a pure WC film, but higher SiC contents do not strongly affect hardness. XRD studies show the SiC had a disordering effect. TEM results showed that WC films had coarse porous structure, but films with a low silicon carbide content (approximately 10 to 25 at%) had a denser nanocrystalline structure. Samples with greater than 25% SiC were amorphous. The initial hardness increase at lower SiC contents correlated well with the observed densification, but the transition to an amorphous structure did not strongly affect hardness.


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