Early stages of the growth of BaTiO3 thin films studied by Transmission Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 706-707
Author(s):  
M. Grant Norton ◽  
Gerald R. English ◽  
Christopher Scarfone ◽  
C. Barry Carter
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Room Temperature ◽  
High Temperature Superconductors ◽  
Pulsed Laser ◽  
Target Material ◽  
Pulsed Laser Ablation ◽  
Cubic Phase ◽  
Transmission Electron ◽  
Tetragonal Form

Barium titanate (BaTiO3) may be used in a number of thin-film applications in electronic and optoelectronic devices. For these devices the formation of epitactic films of the correct stoichiometry and phase is essential. In particular, the tetragonal form of BaTiO3, which is stable at room temperature, exhibits ferro-, pyro- and piezoelectric properties. It is desirable to form films of the tetragonal phase directly and thus to avoid formation of either amorphous or polycrystalline material or to form material of the non-ferroelectric cubic phase. Recently two techniques, pulsed-laser ablation and reactive evaporation, have been used to form BaTiO3 thin-films. In the present study BaTiO3 thin-films have been formed using the pulsed-laser ablation technique. Pulsed-laser ablation is now widely used to produce thin-films of the high temperature superconductors and has many advantages over other techniques, in particular the formation of films which maintain the stoichiometry of the target material and by controlling the processing conditions the formation of films having defined crystalline phases.

Epitaxy of barium titanate thin films grown on MgO by pulsed-laser ablation

1991 ◽  
Vol 6 (10) ◽  
pp. 2022-2025 ◽  
Author(s):  
M. Grant Norton ◽  
Christopher Scarfone ◽  
Jian Li ◽  
C. Barry Carter ◽  
James W. Mayer
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Barium Titanate ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Oxygen Stoichiometry ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Film Substrate ◽  
Α Particles

Thin films of barium titanate (BaTiO3) have been deposited by pulsed-laser ablation onto (001)-oriented MgO substrates. The films were epitactic with the c-axis perpendicular to the film-substrate interface, as evidenced by both transmission electron microscopy (TEM) and ion-channeling techniques. The elastic resonance of 3.045 MeV α-particles, generating the 16O(α, α)16O reaction was used to determine the oxygen stoichiometry of the film and the minimum yield based on the oxygen peaks, thereby enabling conclusions to be drawn about the crystalline perfection of the oxygen sublattice.

Synthesis and properties of p-type nitrogen-doped ZnO thin films by pulsed laser ablation of a Zn-rich Zn3N2 target

2007 ◽  
Vol 22 (8) ◽  
pp. 2339-2344 ◽  
Author(s):  
A. Allenic ◽  
W. Guo ◽  
Y.B. Chen ◽  
G.Y. Zhao ◽  
X.Q. Pan ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Zno Thin Films ◽  
Zno Films ◽  
Transmission Electron ◽  
Columnar Grains ◽  
P Type ◽  
20 Nm

Epitaxial ZnO thin films doped uniformly with nitrogen at 1020 atoms/cm3 were fabricated by pulsed laser ablation of a Zn-rich Zn3N2 target. The films grown at 300 °C and annealed at 600 °C in O2 showed p-type conductivity. Two acceptor levels at 105 and 224 meV were determined by temperature-dependent Hall and photoluminescence measurements of the p-type samples. Transmission electron microscopy studies revealed that the p-type ZnO films consist of 10–20 nm columnar grains with a high density of defects and grain boundaries that may facilitate the annihilation of native donors and the activation of acceptors during postdeposition annealing.

Room-temperature deposition of nanocrystalline PbWO 4 thin films by pulsed laser ablation

2006 ◽  
Vol 84 (1-2) ◽  
pp. 181-185 ◽  
Author(s):  
J.H. Ryu ◽  
J.-W. Yoon ◽  
K.B. Shim ◽  
N. Koshizaki
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Temperature Deposition

Laser-Assisted Synthesis of Amorphous/Pseudoamorphous GaN Thin Films and Nanostructures

2006 ◽  
Vol 317-318 ◽  
pp. 585-588
Author(s):  
Seung Hwan Shim ◽  
Naoto Koshizaki ◽  
Jong Won Yoon ◽  
Kwang Bo Shim
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Laser Ablation ◽  
Chemical Composition ◽  
Room Temperature ◽  
Optical Band Gap ◽  
Laser Energy ◽  
Stoichiometric Composition ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation

Amorphous/pseudoamorphous GaN was prepared by pulsed-laser ablation at room temperature without any heat treatment. The structure and chemical composition of the specimens were systematically investigated. Laser ablation at low Ar pressure (<50Pa) led to deposition of smooth Ga-rich films, which is independent with laser energy. Under same pressures, as laser energy increased, the film stoichiometry changed from Ga-rich to near stoichiometric composition. Varying background Ar pressure strongly affected the product structure showing little effect on the chemical composition. Under higher pressure than 100 Pa, fine nanoparticles with a size of 5 nm rather than films were deposited on substrate due to the increased collision by plume confining. The optical band-gap of the deposited a-GaN is 2.8 eV for thin films and 3.9 eV for nanoparticles.

Microstructure and optical properties of nanocrystalline CaWO4 thin films deposited by pulsed laser ablation in room temperature

2007 ◽  
Vol 441 (1-2) ◽  
pp. 146-151 ◽  
Author(s):  
Jeong Ho Ryu ◽  
Sin Young Bang ◽  
Woo Sik Kim ◽  
Gyeong Seon Park ◽  
Kang Min Kim ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Laser Ablation ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation

Formation of Hydrogen-passivated Silicon Nanochains by Pulsed Laser Ablation without Thermal Annealing

2004 ◽  
Vol 832 ◽  
Author(s):  
Mitsuru Inada ◽  
Ikurou Umezu ◽  
Shukichi Tanaka ◽  
Shinro Mashiko ◽  
Akira Sugimura
Keyword(s):  
Laser Ablation ◽  
Room Temperature ◽  
Crystalline Silicon ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Hydrogen Gas ◽  
Transmission Electron ◽  
Silicon Target ◽  
Gas Atmosphere ◽  
Passivated Silicon

ABSTRACTHydrogen-passivated silicon nanochains were synthesized by pulsed laser ablation of silicon target in hydrogen gas atmosphere at room temperature. When the hydrogen gas pressure was higher than 670Pa, nanochains, which have crystalline silicon core, were formed. Transmission electron microscopy showed the silicon nanochains consist of connections of silicon nanocrystals with mean diameter of 4.6 nm. It is of great interest that the silicon nanochain has crystalline structure without any intentional annealing process. Optical properties of the hydrogen-passivated silicon nanochains were presented.

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