C-Axis Perpendicularly Oriented Barium Ferrite Thin Film Media On Silicon Substrate

1999 ◽  
Vol 577 ◽  
Author(s):  
Zailong Zhuang ◽  
Mark H. Kryder ◽  
Robert M. White ◽  
David E. Laughlin

ABSTRACTBarium ferrite thin films with excellent perpendicular c-axis orientation were successfully fabricated on Si substrate without any buffer layer. To compensate for possible barium deficiency due to the inter-diffusion between films and substrate, a barium-rich target was used. For a 900 Å-thick film, the perpendicular remanent squareness is about 0.9, while the in-plane remanent squareness is about 0.3. The saturation magnetization (Ms) is about 220 emu/cc, while the coercivity is around 3500 Oe. X-ray diffraction (XRD) results show the (001) perpendicular c-axis texture in the films. It was also found that the rapid thermal annealing conditions greatly affect the magnetic properties of barium ferrite films. With a certain flow rate of oxygen gas in the rapid thermal annealer (RTA), barium ferrite films generally crystallize with good perpendicular c-axis texture. Without oxygen gas, the hexagonal barium ferrite phase fails to develop; instead spinel Fe 30 4 phase forms. The reason for the collapsing of hexagonal barium ferrite texture is thought to be an oxygen deficiency in the barium ferrite films due to the reduction of oxygen in the films during the high temperature annealing.

1999 ◽  
Vol 562 ◽  
Author(s):  
Zailong Zhuang ◽  
Mark H. Kryder ◽  
Robert M. White ◽  
David E. Laughlin

ABSTRACTBarium ferrite thin films with excellent perpendicular c-axis orientation were successfully fabricated on Si substrate without any buffer layer. To compensate for possible barium deficiency due to the inter-diffusion between films and substrate, a barium-rich target was used. For a 900 Å-thick film, the perpendicular remanent squareness is about 0.9, while the in-plane remanent squareness is about 0.3. The saturation magnetization (Ms) is about 220 emu/cc, while the coercivity is around 3500 Oe. X-ray diffraction (XRD) results show the (001) perpendicular c-axis texture in the films. It was also found that the rapid thermal annealing conditions greatly affect the magnetic properties of barium ferrite films. With a certain flow rate of oxygen gas in the rapid thermal annealer (RTA), barium ferrite films generally crystallize with good perpendicular c-axis texture. Without oxygen gas, the hexagonal barium ferrite phase fails to develop; instead spinel Fe3O4 phase forms. The reason for the collapsing of hexagonal barium ferrite texture is thought to be an oxygen deficiency in the barium ferrite films due to the reduction of oxygen in the films during the high temperature annealing.


1998 ◽  
Vol 526 ◽  
Author(s):  
W. D. Song ◽  
Y.F. Lu ◽  
J.P. Wang ◽  
X.T. Zeng ◽  
L. Lu ◽  
...  

AbstractBarium ferrite films with high coercivity (>2000 Oe) have been prepared on single crystal sapphire substrates by laser in-situ deposition. The structures of these films were characterized by x-ray diffractometry. X-ray diffraction pattern shows a preferential c-axis orientation normal to the film plane at a high deposition temperature and a random orientation at a lower deposition temperature. The magnetic properties of the films were analysed by a Vibrating Sample Magnetometer (VSM) and surface morphology was analysed by an Atomic Force Microscope (AFM).


2003 ◽  
Vol 785 ◽  
Author(s):  
George J. Kavarnos ◽  
Thomas Ramotowski

ABSTRACTChlorinated poly(vinylidene fluoride/trifluoroethylene) terpolymers are remarkable examples of high strain electrostrictive materials. These polymers are synthesized by copolymerizing vinylidene fluoride and trifluoroethylene with small levels of a third chlorinated monomer. The electromechanical responses of these materials are believed to originate from the chlorine atom, which, by its presence in the polymer chains and by virtue of its large van der Waals radius, destroys the long-range crystalline polar macro-domains and transforms the polymer from a normal to a high-strain relaxor ferroelectric. To exploit the strain properties of the terpolymer, it is desirable to understand the structural implications resulting from the presence of the chlorinated monomer. To this end, computations have been performed on model superlattices of terpolymers using quantum-mechanical based force fields. The focus has been on determining the energetics and kinetics of crystallization of the various polymorphs that have been identified by x-ray diffraction and fourier transform infrared spectroscopy. The chlorinated monomer is shown to act as a defect that can be incorporated into the lamellar structures of annealed terpolymer without a high cost in energy. The degree of incorporation of the chlorinated monomer into the crystal lattice is controlled by annealing conditions and ultimately determines the ferroelectric behavior of the terpolymers.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Gyu-bong Cho ◽  
Tae-hoon Kwon ◽  
Tae-hyun Nam ◽  
Sun-chul Huh ◽  
Byeong-keun Choi ◽  
...  

LiNiO2thin films were fabricated by RF magnetron sputtering. The microstructure of the films was determined by X-ray diffraction and field-emission scanning electron microscopy. The electrochemical properties were investigated with a battery cycler using coin-type half-cells. The LiNiO2thin films annealed below 500°C had the surface carbonate. The results suggest that surface carbonate interrupted the Li intercalation and deintercalation during charge/discharge. Although the annealing process enhanced the crystallization of LiNiO2, the capacity did not increase. When the annealing temperature was increased to 600°C, the FeCrNiO4oxide phase was generated and the discharge capacity decreased due to an oxygen deficiency in the LiNiO2thin film. The ZrO2-coated LiNiO2thin film provided an improved discharge capacity compared to bare LiNiO2thin film suggesting that the improved electrochemical characteristic may be attributed to the inhibition of surface carbonate by ZrO2coating layer.


2020 ◽  
Vol 28 ◽  
pp. 14-19
Author(s):  
Zamir V. Shomakhov ◽  
Akhmed M. Karmokov ◽  
Oleg A. Molokanov ◽  
Olga O. Molokanova ◽  
Rita Y. Karmokova ◽  
...  

Studies of the temperature dependence of the electrical properties of glasses show that the high-temperature annealing in glasses observed irreversible processes. These processes lead to changes in electrical conductivity, dielectric permittivity, and hence the electrical capacitance, dielectric loss tangent, and other parameters. Obviously, this is due to structural changes in the glass as a result of high-temperature annealing. In this regard, this paper presents studies of structural and phase transformations in glasses used for the production of microchannel plates in the process of high-temperature annealing in vacuum and in the air atmosphere at different times. The studies were conducted by x-ray phase and X-ray diffraction analysis, as well as X-ray fluorescence elemental analysis.


2001 ◽  
Vol 666 ◽  
Author(s):  
Fumiaki Mitsugi ◽  
Tomoaki Ikegami ◽  
Kenji Ebihara ◽  
Jagdish Narayan ◽  
Alexander M. Grishin

ABSTRACTWe prepared colossal magnetoresistive La0.8Sr0.2MnO3 thin films on the MgO, SrTiO3 and LaAlO3 single crystal substrates using KrF excimer pulsed laser ablation technique. The structural and electrical properties of the La0.8Sr0.2MnO3 thin films which were strained by the lattice mismatch are reported. The in-plane lattice mismatch between the La0.8Sr0.2MnO3 and MgO, SrTiO3 and LaAlO3 substrates are -7.8 %, -0.5 % and +2.3 %, respectively. The X-ray diffraction spectra of the films exhibited c-axis orientation. In the case of the La0.8Sr0.2MnO3 / LaAlO3 thin films with thickness over 100 nm, the divided (00l) peaks were observed. The surface morphology and transport property of the strongly stressed La0.8Sr0.2MnO3 / LaAlO3 were different from those of La0.8Sr0.2MnO3 / MgO and La0.8Sr0.2MnO3 / SrTiO3thin films.


2011 ◽  
Vol 418-420 ◽  
pp. 293-296
Author(s):  
Qiu Yun Fu ◽  
Peng Cheng Yi ◽  
Dong Xiang Zhou ◽  
Wei Luo ◽  
Jian Feng Deng

Abstract. In this article, nano-ZnO films were deposited on SiO2/Si (100) substrates by RF (radio frequency) magnetron sputtering using high purity (99.99%) ZnO target. The effects of deposition time and annealing temperature have been investigated. XRD (X-ray diffraction) and FSEM (Field Emission Scanning Electron Microscopy) were employed to characterize the quality of the films. The results show that the ZnO film with thickness of 600nm annealed at 900°C has higher quality of both C-axis orientation and crystallization. And for the Zone film with thickness of 300nm annealed at 850°C, the quality of both C-axis orientation and crystallization is higher than that annealed at 900°C and 950°C.


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