The Structure and Magnetic Properties of NiZn-Ferrite Films Deposited by Magnetron Sputtering at Room Temperature

2013 ◽  
Vol 690-693 ◽  
pp. 1702-1706 ◽  
Author(s):  
Shuang Jun Nie ◽  
Hao Geng ◽  
Jun Bao Wang ◽  
Lai Sen Wang ◽  
Zhen Wei Wang ◽  
...  

NiZn-ferrite thin films were deposited onto silicon and glass substrates by radio frequency magnetron sputtering at room temperature. The effects of the relative oxygen flow ratio on the structure and magnetic properties of the thin films were investigated. The study results reveal that the films deposited under higher relative oxygen flow ratio show a better crystallinity. Static magnetic measurement results indicated that the saturation magnetization of the films was greatly affected by the crystallinity, grain dimension, and cation distribution in the NiZn-ferrite films. The NiZn-ferrite thin films with a maximum saturation magnetization of 151 emucm-3, which is about 40% of the bulk NiZn ferrite, was obtained under relative oxygen flow ratio of 60%.

2005 ◽  
Vol 875 ◽  
Author(s):  
A. R. Abuzir ◽  
W. J. Yeh

AbstractDue to their large magnetic anisotropy perpendicular to the film plane, barium ferrite thick films (BaFe12O19, or BaM) with c-axis orientation are attractive candidates for microwave applications [1,2]. Barium ferrite thin films on silicon substrates without under layer have been deposited under various conditions by RF magnetron sputtering. The structure of the as-grown films is amorphous. External annealing in air has been done at 950°C for ten minutes to crystallize the films. C-axis oriented thin films with squareness of about 0.87 and coercivity of about 3.8KOe are obtained.Thick BaM films with c-axis orientation are difficult to achieve with one single deposition. Multilayer technique looks promising to grow thick films [3]. The external annealing process is difficult to incorporate with the multilayer procedure. An in-situ annealing procedure has been developed to obtain films, which can be used as the basic component for future multilayer deposition. Barium ferrites are first magnetron sputtered on bare silicon substrates in Ar + O2 atmosphere at substrate temperature of 500-600°C, the deposition pressure was kept about 0.008 torr. After the deposition, the temperature of the substrate is immediately increased to about 860°C for ten minutes in 140 torr of argon (80%) and oxygen (20%) mixture of gas, which was introduced into the chamber without breaking the vacuum. With the in-situ process, c-axis oriented thin films of 0.88 squareness and coercivity value of about 4.3KOe are obtained.Both annealing methods seem to have the similar effect on the perpendicular squareness and coercivity at various film thicknesses. The average value of the saturation magnetization Ms obtained from the in-situ annealing using multilayer technique is higher than that of the external one. We have grown films up to 1.0 micron thickness using the multilayer technique, in which three layers of 0.3 μm thickness each are deposited until the final thickness is reached. After the deposition of each layer, it was in-situ annealed before starting the deposition of the next layer. With the multilayer technique, coercivity of about 3.5 KOe and average value of the saturation magnetization Ms of about 4.0 K Gauss is obtained.


Author(s):  
A. Bendjerad ◽  
A. Benhaya ◽  
S. Boukhtache ◽  
M. Zergoug ◽  
K. Benyahia

In the present work, thin films of Cr/NiO/Ni are deposited on glass substrates using RF magnetron sputteringtechnique. The uniformity and homogeneity of the prepared films were controlled by varying the power of the source, the target-substrate distance and the pressure of the plasma gas which is argon. In order to test the Preisach Model, we carried outmeasurements according to two directions: parallel and perpendicular to the substrate plane using a Vibrating SampleMagnetometer at room temperature. Good agreement has been obtained by comparing the experimental hysteresis loops to theones determined using Preisach model. We conclude that this model is powerful in predicting the magnetic properties ofmultilayer systems. # Cr/NiO/Ni #MAGNETRON_SPUTTERING #PREISACH MODEL #MAGNETIC_HYSTERESIS


2009 ◽  
Vol 23 (27) ◽  
pp. 5275-5282 ◽  
Author(s):  
JICHENG ZHOU ◽  
DITIAN LUO ◽  
YOUZHEN LI ◽  
ZHENG LIU

Ta 2 O 5 thin films were deposited at different oxygen flow ratio ( O 2/( O 2+Ar) = 10 ~ 80%) by DC reactive magnetron sputtering. Influence of oxygen flow ratio on depositing rate, surface characteristics, microstructure, and optical properties are discussed in this paper. With the increasing of oxygen, deposition rate decreases exponentially, the root mean square roughness and the maximum roughness decrease according to the atom force microscope images. XRD patterns indicate the as-deposited Ta 2 O 5 films are amorphous. Based on the envelop method, the samples' optical constants are calculated from the curve of transmission spectrum. The results indicate that refractive index n increases from 2.01 to 2.20 (λ = 500 nm ) for the oxygen flow ratio increases from 20% to 60%, the extinction coefficient k appears to decrease.


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.


1994 ◽  
Vol 9 (9) ◽  
pp. 2425-2433 ◽  
Author(s):  
Hae Seok Cho ◽  
Min Hong Kim ◽  
Hyeong Joon Kim

We have investigated the effects of process parameters such as rf power, substrate, and gas pressure PAr on preferred orientation, microstructure, and magnetic properties of Ni-Zn-Cu ferrite thin films deposited by conventional rf magnetron sputtering. The texture structure was developed in the ferrite films deposited on the SiO2/Si(100) substrate at low rf power conditions. The ferrite film on the Si(111) substrate always had (111) texture irrespective of process parameters due to lattice matching, but the texture of the ferrite film on SiO2/Si(100) changed from (111) to (100) and finally returned to (111) orientation again with decreasing PAr. Such behavior would occur presumably due to the characteristic atomic stacking sequence corresponding to a given condition of the ion bombardment. The ferrite films deposited at low PAr had a denser microstructure consisting of tightly packed columnar grains with a smoother surface, better adhesion to the substrate, and better crystallinity than those at high PAr. Hc‖ of ferrite film deposited at low PAr was larger than that at high PAr and also larger than Hc⊥ of that deposited at the same PAr because larger compressive stress was induced at low PAr than at high PAr.


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