Domain Structure of Tetragonal Plt Epitaxial Thin Films on Mgo (001) Single Crystal Substrates

1996 ◽  
Vol 433 ◽  
Author(s):  
Y. M. Kang ◽  
J. K. Ku ◽  
S. Baik

AbstractFerroelectric Pb1−xLaxTiO3 (PLT, x = 0.00 ˜ 0.28) thin films have been prepared on MgO(001) substrates using pulsed laser deposition. The degree of c-axis orientation in PLT films increased as the La concentration (x) increased with systematic changes in lattice constants and transformation strains. For x ≥ 12, the PLT films showed full c-axis orientation.In order to understand why the domain evolution in PLT films changes with the La concentration, we have conducted high temperature X-ray diffraction to simulate the cooling process during which the domain structure is evolved. Lattice constants, degree of c-axis orientation, crystal quality of PLT films were characterized as a function of temperature. Lattice constants along substrate normal direction showed similar characteristics with those of powder. The degree of c-axis orientation just after the phase transformation at the Curie temperature also increased with La concentration. The crystal quality, which is quantified by the line width of diffraction peak, is insensitive to La concentration in paraelectric phase. However, it shows significant variation after the domain structure is evolved.

1994 ◽  
Vol 361 ◽  
Author(s):  
Y.M. Kang ◽  
J.K. Ku ◽  
S. Baik

ABSTRACTFerroelectric Pb1−xLaxTi1−x/4(x = 0 ∼ 0.28) epitaxial thin films were prepared on MgO(001), SrTiO3(001), and LaAlO3(001) single crystalline substrates using pulsed laser deposition. The change in lattice constants of PLT films by La concentration, x, was investigated systematically for each substrate. RBS studies revealed that the composition of PLT films is consistent with that of the targets. Lattice constants, degree of c-axis orientation, crystal quality of the PLT films were characterized by symmetric and asymmetric X-ray scans. The strain which occurred during the cubic to tetragonal phase transition seemed to be the major factor determining the c-axis orientation configuration, i.e., 90° domain structure and the crystal quality of PLT films.


2005 ◽  
Vol 891 ◽  
Author(s):  
Shin-ichiro Uekusa ◽  
Kunitoshi Aoki ◽  
Mohammad Zakir Hossain ◽  
Tomohiro Fukuda ◽  
Noboru Miura

ABSTRACTWe prepared β-FeSi2 thin-films by using a Pulsed Laser Deposition (PLD) method and succeeded to observe photoluminescence (PL) around 1.5 μm corresponding to β-FeSi2 band from the long-time and high-temperature annealed β-FeSi2 thin-films. The β-FeSi2 thin-films were ablated on Si(111) substrates heated at 550°C. After ablation, long-time and high-temperature thermal annealing was performed in order to improve the crystal-quality. Annealing times were 5, 10, 20 and 40 hrs, and annealing temperature was kept at 900 °C. Crystallinity was evaluated by an X-ray diffraction (XRD) measurement. We have observed eminent improvement on crystal-quality of β-FeSi2 thin-films. Annealed samples show (220) or (202) X-ray diffraction signals of β-FeSi2 and the full width at half maximum (FWHM) of these peaks were 0.27° although the thickness of the samples decreased with annealing time. Thermal-diffusion of Si atoms was observed from substrate to thin-films. Fe atoms in the ablated thin-films also diffused into the substrate. The relationship between the thickness of β-FeSi2 thin-films and the thermal-diffusion were investigated with rutherford backscattering (RBS) measurement. Maximum photoluminescence intensity around 1.5 μm was observed from the thickest β-FeSi2 thin-film with only 5 hrs annealing.


2001 ◽  
Vol 16 (9) ◽  
pp. 2463-2466 ◽  
Author(s):  
Yong Kwan Kim ◽  
Kyeong Seok Lee ◽  
Sunggi Baik

Epitaxial (Pb1−xSrx)TiO3 (PST, x = 4 0.0–0.24) thin films were grown on MgO(001) single-crystal substrates by pulsed laser deposition. General x-ray diffraction techniques including θ–2θ scan and rocking curve were used to determine lattice constants, degree of c-axis orientation, and crystal quality of the tetragonal thin films. The degree of c-axis orientation in the epitaxial PST films increased as Sr concentration (x) increased, which in turn induces the systematic change in the Curie temperature as well as the transformation strain at and below the Curie temperature. An inverse relation between the c-domain abundances and the transformation strains is established.


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.


2000 ◽  
Author(s):  
Kazuhiko Omote ◽  
T. Kikuchi ◽  
J. Harada ◽  
Masashi Kawasaki ◽  
Akira Ohtomo ◽  
...  

2011 ◽  
Vol 399-401 ◽  
pp. 926-929
Author(s):  
Wei Zhang ◽  
Mei Ling Yuan ◽  
Xian Yang Wang ◽  
Jun Ouyang

BaTiO3(BTO) thin films were grown on (100) SrTiO3(STO) single crystal substrates using the RF-magnetron sputtering technique (RFMS) in both pure argon and mixed Ar/O2(20% O2) atmosphere. A La0.5Sr0.5CoO3(LSCO) layer was deposited as the bottom electrode by a 90° off-axis single-target RFMS. θ-2θ X-ray diffraction measurements showed that BTO thin films grown in both cases had a highly preferred c-axis orientation (001). From hysteresis measurements, it was confirmed that both films are ferroelectric. The ferroelectric polarizations 2Pr were 6.6 μC/cm2and 27.1 μC/cm2, for the BTO films grown in pure argon and in mixed Ar/O2atmosphere, respectively.


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