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Effect of Substrates on the Properties of ZnO Thin Films Grown by Pulsed Laser Deposition  [PDF]
Adel Taabouche, Abderrahmane Bouabellou, Fouad Kermiche, Faouzi Hanini, Sarah Menakh, Yacine Bouachiba, Tahar Kerdja, Chawki Benazzouz, Mohamed Bouafia, Saad Amara
Advances in Materials Physics and Chemistry (AMPC) , 2013, DOI: 10.4236/ampc.2013.34031
Abstract: Polycrystalline zinc oxide (ZnO) thin films have been deposited at 450°C onto glass and silicon substrates by pulsed laser deposition technique (PLD). The used source was a KrF excimer laser (248 nm, 25 ns, 5 Hz, 2 J/cm2). The effects of glass and silicon substrates on structural and optical properties of ZnO films have been investigated. X-ray diffraction patterns showed that ZnO films are polycrystalline with a hexagonal wurtzite—type structure with a strong (103) orientation and have a good crystallinity on monocrystalline Si(100) substrate. The thickness and compositional depth profile were studied by Rutherford Backscattering spectrometry (RBS). The average transmittance of ZnO films deposited on glass substrate in the visible range is 70%.
High quality epitaxial FeSe0.5Te0.5 thin films grown on SrTiO3 substrates by pulsed laser deposition  [PDF]
E. Bellingeri,R. Buzio,A. Gerbi,D. Marre',S. Congiu,M. R. Cimberle,M. Tropeano,A. S. Siri,A. Palenzona C. Ferdeghini
Physics , 2009, DOI: 10.1088/0953-2048/22/10/105007
Abstract: Superconducting epitaxial FeSe0.5Te0.5 thin films were prepared on SrTiO3 (001) substrates by pulsed laser deposition. The high purity of the phase, the quality of the growth and the epitaxy were studied with different experimental techniques: X-rays diffraction, reflection high energy electron diffraction, scanning tunnelling microscopy and atomic force microscopy. The substrate temperature during the deposition was found to be the main parameter governing sample morphology and superconducting critical temperature. Films obtained in the optimal conditions show an epitaxial growth with c axis perpendicular to the film surface and the a and b axis parallel to the substrates one, without the evidence of any other orientation. Moreover, such films show a metallic behavior over the whole measured temperature range and critical temperature above 17K, which is higher than the target one.
Decisive role of oxygen vacancy in ferroelectric vs. ferromagnetic Mn-doped BaTiO3 thin films  [PDF]
Yao Shuai,Shengqiang Zhou,Danilo Bürger,Helfried Reuther,Ilona Skorupa,Varun John,Manfred Helm,Heidemarie Schmidt
Physics , 2011, DOI: 10.1063/1.3576125
Abstract: Single-phase perovskite 5 at.% Mn-doped and undoped polycrystalline BaTiO3 thin films have been grown under different oxygen partial pressures by pulsed laser deposition on platinum-coated sapphire substrates. Ferroelectricity is only observed for the Mn-doped and undoped BaTiO3 thin films grown under relatively high oxygen partial pressure. Compared to undoped BaTiO3, Mn-doped BaTiO3 reveals a low leakage current, increased dielectric loss, and a decreased dielectric constant. Ferromagnetism is seen on Mn-doped BaTiO3 thin films prepared under low oxygen partial pressure and is attributed to the formation of bound magnetic polarons (BMPs). This BMP formation is enhanced by oxygen vacancies. The present work confirms a theoretical work from C. Ederer and N. Spaldin on ferroelectric perovskites [Nature Mat. 3, 849 (2004)] which shows that the existence of ferroelectricity is incompatible with the existence of a spontaneous magnetization in Mn-doped BaTiO3 thin films.
Epitaxial Ba2IrO4 thin-films grown on SrTiO3 substrates by pulsed laser deposition  [PDF]
J. Nichols,O. B. Korneta,J. Terzic,G. Cao,J. W. Brill,S. S. A. Seo
Physics , 2014, DOI: 10.1063/1.4870049
Abstract: We have synthesized epitaxial Ba2IrO4 (BIO) thin-films on SrTiO3 (001) substrates by pulsed laser deposition and studied their electronic structure by dc-transport and optical spectroscopic experiments. We have observed that BIO thin-films are insulating but close to the metalinsulator transition boundary with significantly smaller transport and optical gap energies than its sister compound, Sr2IrO4. Moreover, BIO thin-films have both an enhanced electronic bandwidth and electronic-correlation energy. Our results suggest that BIO thin-films have great potential for realizing the interesting physical properties predicted in layered iridates.
The coexistence of ferroelectricity and ferromagnetism in Mn-doped BaTiO3 thin films

Ding Bin-Feng,Zhou Sheng-Qiang,

中国物理 B , 2011,
Abstract: 5-at% Mn-doped and undoped BaTiO3 thin films have been grown under different oxygen partial pressures by Pulsed Laser Deposition (PLD) on platinum-coated sapphire substrates. X-ray diffraction (XRD) measurements for all the thin films reveal a similar polycrystalline single-phase perovskite structure. Ferroelectricity is observed in the Mn-doped and undoped BaTiO3 thin films grown under relatively high oxygen partial pressure. Ferromagnetic coupling of the Mn dopant ions, on the other hand, is only seen in Mn-doped BaTiO3 thin films prepared under low oxygen partial pressure in a wide temperature range from 5 K to 300 K, and is attributed to the enhanced exchange coupling between Mn dopants and electrons at oxygen vacancies. Our results show that the leakage current is decreased with the doped Mn, but increases the dielectric loss and decreases the dielectric constant, and the ferroelectricity is impaired. To produce ferromagnetism, oxygen vacancies are necessary, which unfortunately increase the leakage current. This confirms that the mutual interplay between the ferroelectricity and ferromagnetism can be tuned by exchange coupling of the doped-Mn and oxygen vacancies in the BaTiO3 thin films.
Highly-oriented A1N Thin Films on Si(100) Substrates by Pulsed Laser Deposition

ZHANG Xia,CHEN Tong-Lai,LI Xiao-Min,

无机材料学报 , 2005,
Abstract: Highly crystalline quality A1N thin films were successfully grown on Ti0.8Al0.2N/TiNbuffered p-Si(100) substrates by pulsed laser deposition (laser source: KrF). X-ray diffraction (XRD) and reflective high energy electron diffraction (RHEED) were employed to characterize the as-grown films. The results show that A1N thin films are (001) oriented and grown with 2D layer growth mode. The growth modes of thin films rely on the kinds of buffer layers: A1N thin films on Si wafers or MgO/Si substrates are 3D island grown; whereas those on Ti0.8Al0.2N/TiN/Si substrates are 2D layer grown. In addition, the laser energy density has considerable effects on the crystalline quality of A1N thin films: over high energy leads to rough surface and big particles. The partial nitrogen pressure can make A1N thin films (100) orientation instead of (001) orientation.
Optical properties of laser ablated Ag:BaTiO3 composite films

Yang Guang,Chen Zheng-Hao,
杨 光

物理学报 , 2006,
Abstract: Nanocomposite films composed of Ag particles embedded in BaTiO3 matrix were grown on MgO(100) substrates by pulsed laser deposition. The structures of the films were determined by X-ray diffraction. The size and shape of the Ag particles were observed by transmission electron microscopy. The X-ray photoelectron spectroscopy results showed that Ag is in the metallic state. The optical absorption properties were measured from 300 to 800nm, and the absorption peaks due to the surface plasmon resonance of Ag particles were observed. With increasing annealing temperature and Ag concentration, the peak absorption increased and shifted to longer wavelength (red-shift).
Large third-order optical nonlinearity in Au nanometre particle doped BaTiO3 composite films near the resonant frequency
Large third—order optical nonlinearity in Au nanomeytre particle doped BaTiO3 composite films near the resonant frequency

中国物理 B , 2002,
Abstract: Nanometre-sized gold particles embedded in BaTiO3 composite thin films (Au/BaTiO3) were fabricated by the pulsed laser deposition technique. The films were grown on MgO (100) substrates at 700℃. The crystalline property of the films was studied with x-ray diffraction. X-ray photoelectron spectroscopy was used to check the Au composition and chemical nature for the deposited films. The absorption peak due to the surface plasmon resonance of Au particles was observed at the wavelength of about 570 nm, which increased as the metal particle size was increased. The nonlinear optical properties of the Au/BaTiO3 films were determined using the z-scan method at the wavelength of 532 nm, which was close to the resonant frequency. The real and imaginary parts of the third-order nonlinear susceptibility χ(3) at an Au concentration of about 6.7 at.% were determined to be 6.62×10-7 esu and -6.24×10-8 esu, respectively. The films showed a very large absorption, masking the nonlinear refraction effect at high metal concentrations.
Optical Properties of Co--BaTiO3/Mg(100) Nano-Composite Films Grown by Pulsed Laser Deposition Method

WU Wei-Dong,WANG Feng,GE Fang-Fang,BAI Li,LEI Hai-Le,TANG Yong-Jian,JU Xin,CHEN Zheng-Hao,SUN Wei-Guo,

中国物理快报 , 2008,
Abstract: Co nanoparticles embedded in a BaTiO3 matrix, namely Co--BaTiO3 nano-composite films are grown on Mg(100) single crystal substrates by the pulsed laser deposition (PLD) method at 650°C. Optical properties of the Co--BaTiO3 nano-composite films are examined by absorption spectra (AS) and photoluminescence (PL) spectra. The results indicate that the concentration of Co nano-particles strongly influences the electron transition of the Co--BaTiO3 nano-composite films. The PL emission band ranging from 1.9 to 2.2eV is reported. The AS and PL spectra suggest that the band gap is in the range of 3.28--3.7eV.


物理学报 , 1997,
Abstract: 用脉冲激光淀积方法在SrTiO3衬底上制备了BaTiO3/YBa2Cu3O7-δ(铁电/超导)双层膜,X射线分析表明BaTiO3薄膜是高度c取向的.对BaTiO3薄膜的介电和铁电性能进行了实验研究.观察到铁电薄膜特有的电滞线和蝶型C-V曲线,薄膜呈现出较好的铁电性,在铁电随机存储等领域有重要的应用前景
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