Influence of Oxygen Contamination on Magnetic Properties of Amorphous and Nanocrystallized FeCuSiNbB Thin Films

2009 ◽  
Vol 152-153 ◽  
pp. 3-6 ◽  
Author(s):  
Johan Moulin ◽  
Bhaskar Kaviraj ◽  
El Houcine Oubensaïd ◽  
Francisco Alves ◽  
Uday P. Deshpande ◽  
...  

Thin films of amorphous FeCuSiNbB alloy have been deposited by RF sputtering with various deposition rates. The bulk oxygen content has been characterized using EDS and XPS. Its dependence on deposition rate shows that water vapour in the sputtering chamber is at the origin of the contamination. It allows also estimating the adsorption coefficient of the oxygen on the sample to be around 15 % at 350 K. The magnetic hardness and the resistivity increase with the contamination in oxygen. In devitrified films, this increase is also related to an enrichment of the residual amorphous matrix in oxygen.

2017 ◽  
Vol 73 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Ali Karpuz ◽  
Salih Colmekci ◽  
Hakan Kockar ◽  
Hilal Kuru ◽  
Mehmet Uckun

AbstractThe structural and corresponding magnetic properties of Ni/Cu films sputtered at low and high deposition rates were investigated as there is a limited number of related studies in this field. 5[Ni(10 nm)/Cu(30 nm)] multilayer thin films were deposited using two DC sputtering sources at low (0.02 nm/s) and high (0.10 nm/s) deposition rates of Ni layers. A face centered cubic phase was detected for both films. The surface of the film sputtered at the low deposition rate has a lot of micro-grains distributed uniformly and with sizes from 0.1 to 0.4 μm. Also, it has a vertical acicular morphology. At high deposition rate, the number of micro-grains considerably decreased, and some of their sizes increased up to 1 μm. The surface of the Ni/Cu multilayer deposited at the low rate has a relatively more grainy and rugged structure, whereas the surface of the film deposited at the high rate has a relatively larger lateral size of surface grains with a relatively fine morphology. Saturation magnetisation, Ms, values were 90 and 138 emu/cm3 for deposition rates of 0.02 and 0.10 nm/s, respectively. Remanence, Mr, values were also found to be 48 and 71 emu/cm3 for the low and high deposition rates, respectively. The coercivity, Hc, values were 46 and 65 Oe for the low and high Ni deposition rates, respectively. The changes in the film surfaces provoked the changes in the Hc values. The Ms, Mr, and Hc values of the 5[Ni(10 nm)/Cu(30 nm)] films can be adjusted considering the surface morphologies and film contents caused by the different Ni deposition rates.


2004 ◽  
Vol 855 ◽  
Author(s):  
J. H. Tan ◽  
V. H. Guerrero ◽  
R. C. Wetherhold ◽  
W. A. Anderson

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.


2007 ◽  
Vol 558-559 ◽  
pp. 975-978
Author(s):  
L.V. Tho ◽  
K.E. Lee ◽  
Cheol Gi Kim ◽  
Chong Oh Kim ◽  
W.S. Cho

Nanocrystalline CoFeHfO thin films have been fabricated by RF sputtering method. Co52Fe23Hf10O15 thin film is observed, exhibit good magnetic properties with magnetic coercivity (Hc) of 0.18 Oe; anisotropy fild (Hk) of 49 Oe; saturation magnetization (4лMs) of 21 kG, and electrical resistivity (ρ) of 300 01cm. The frequency response of permeability of the film is excellent. The effect of microstructure on the electrical and magnetic properties of thin film was studied using X-ray diffraction (XRD) analysis and conventional transmission electron microscopy (TEM). The results showed that excellent soft magnetic properties were associated with granular nannoscale grains of α-CoFe and α-Co(Fe) phases.


2003 ◽  
Vol 18 (5) ◽  
pp. 1035-1038 ◽  
Author(s):  
J. Gonzáz

Results on microstructure and coercivity of current-annealed Fe73.5Cu1Nb3Si13.5B9 amorphous alloy treated at different current densities (12–56 A/mm2) and duration (0.5–720 min) are presented. Saturation magnetization and coercivity dependencies with the current density of the nanocrystalline samples is explained by considering the presence of two phases: nanocrystals of Fe(Si) body-centered cubic (bcc) grains and the residual amorphous matrix. An increase in the magnetic hardness observed when the sample was heated by current densities, giving rise to an increase in the sample temperature above the Curie point of the residual amorphous matrix, could be ascribed to exchange and dipolar decoupling of the Fe(Si)-bcc grains.


1976 ◽  
Vol 28 (12) ◽  
pp. 746-748 ◽  
Author(s):  
Yoshinori Mimura ◽  
Nobutake Imamura

2004 ◽  
Vol 272-276 ◽  
pp. 1160-1161 ◽  
Author(s):  
Z.G Sun ◽  
H Kuramochi ◽  
M Mizuguchi ◽  
F Takano ◽  
Y Semba ◽  
...  

2015 ◽  
Vol 1805 ◽  
Author(s):  
Adrian Camacho-Berrios ◽  
Victor Pantojas ◽  
Wilfredo Otaño

ABSTRACTZnO thin films were deposited using the DC pulsed magnetron sputtering technique to study how composition and structure influences their magnetic properties. Low sputtering powers and high substrate temperatures were used to increase adatom mobility during deposition, resulting in increased crystallite size and reduced residual stress in the films. Another set of ZnO films were Mn-doped using a second magnetron gun and the amount of doping was changed by controlling the RF sputtering power. For these films, the crystallite size increased with the amount of Mn. The magnetic properties of these materials were counterintuitive; not intentionally doped ZnO showed the highest magnetization and magnetization decreased with increasing Mn concentration.


2014 ◽  
Vol 1025-1026 ◽  
pp. 765-769
Author(s):  
Aleksandr Kotvitckii ◽  
Aleksandr Dubinetc ◽  
Konstantin Ermaov ◽  
Evgeny B. Modin ◽  
Evgeny Vladislavovich Pustovalov ◽  
...  

In this paper, the technique of irradiation of thin films by Ga+ ions inside of scanning electron microscope, by a focused ion beam is developed. The influence of irradiation on magnetic properties of thin epitaxial films of Co, grown by molecular beam epitaxy in ultrahigh vacuum on a silicon surface with a intermediate layer of copper atoms. It has been shown that low radiation doses lead to an increase of magnetic hardness of the samples. At higher doses, there is a decrease of coercive force, which is apparently due to a change of crystalline structure of the material. An interesting fact is that in the dose range of 1012-1015 the relative remanences is practically unchanged and only at higher doses the magnetic properties of the film worsen.


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