Examination of Particles and Outgrowths on the Surface of Epitaxial Yba2Cu3O7 Thin Films

1994 ◽  
Vol 341 ◽  
Author(s):  
M. Grant Norton ◽  
Rand R. Biggers ◽  
I. Maartense ◽  
E. K. Moser ◽  
Jeff L. Brown

AbstractThe surface morphology of Yba2Cu3O7 thin films formed on (001)-oriented LaAlO3 substrates by pulsed-laser deposition has been examined using electron and scanning probe microscopies. The observed surface features can be divided into two types: particles formed as a result of material (often molten) ejected from the target and outgrowths formed as a result of nucleation and growth processes on the substrate and/or the film surface. Where both types of surface feature occur on a particular film the outgrowths are always more numerous. The density of outgrowths is strongly related to the deposition parameters and, as a consequence, with the film growth mechanism.

1994 ◽  
Vol 361 ◽  
Author(s):  
William Jo ◽  
T.W. Noh

ABSTRACTUsing pulsed laser deposition, Bi4Ti3O12 thin films were grown on (0001) and (1102) surfaces of Al2O3. Substrate temperature from 700 to 800 °C and oxygen pressure from 50 to 1000 mtorr were varied, and their effects on Bi4Ti3O12 film growth behavior was investigated. Only for a narrow range of deposition parameters, can highly oriented Bi4Ti3O12(104) films be grown on Al2O3(0001). Further, epitaxial BTO(004) films can be grown on Al2O3(1102). The growth behavior of preferential BTO film orientations can be explained in terms of atomic arrangements in the Bi4Ti3O12 and the Al2O3 planes.


Author(s):  
M. Grant Norton ◽  
Rand R. Biggers ◽  
Iman Maartense ◽  
E. K. Moser ◽  
Jeff L. Brown

Electron and scanning probe microscopies are used to examine the microstructure and surface topography of YBa2Cu3O7 (YBCO) thin films formed by pulsed-laser deposition (PLD). A major emphasis of this work has been the correlation of the observed microstructural features and the deposition parameters.The formation of microscopic features on the surface of thin films deposited by PLD seems to be an undesirable and almost unavoidable feature of this process. One such feature is often associated with microstructural changes produced in the target during laser irradiation. These are apparently spherical particles with diameters ranging from 0.1 to 10μm. These particles are produced by melting of the target and the subsequent solidification of the molten ejecta. Particles may also be produced as a result of changes in the surface morphology of the target during laser irradiation. However, notall surface features observed on the films deposited by PLD are due to ejecta from the target. Figure 1 shows an atomic force microscope (AFM) image of a YBCO film grown on a (100)-oriented LaAlO3 substrate. Usually films grown with our typical deposition conditions on (100)-oriented LaAlO3 substrates arepredominantly c-axis oriented. The film is approximately 150 nm thick. Different types of outgrowth are visible on the film surface.


2010 ◽  
Vol 75 ◽  
pp. 202-207
Author(s):  
Victor Ríos ◽  
Elvia Díaz-Valdés ◽  
Jorge Ricardo Aguilar ◽  
T.G. Kryshtab ◽  
Ciro Falcony

Bi-Pb-Sr-Ca-Cu-O (BPSCCO) and Bi-Pb-Sb-Sr-Ca-Cu-O (BPSSCCO) thin films were grown on MgO single crystal substrates by pulsed laser deposition. The deposition was carried out at room temperature during 90 minutes. A Nd:YAG excimer laser ( = 355 nm) with a 2 J/pulse energy density operated at 30 Hz was used. The distance between the target and substrate was kept constant at 4,5 cm. Nominal composition of the targets was Bi1,6Pb0,4Sr2Ca2Cu3O and Bi1,6Pb0,4Sb0,1Sr2Ca2Cu3OSuperconducting targets were prepared following a state solid reaction. As-grown films were annealed at different conditions. As-grown and annealed films were characterized by XRD, FTIR, and SEM. The films were prepared applying an experimental design. The relationship among deposition parameters and their effect on the formation of superconducting Bi-system crystalline phases was studied.


2013 ◽  
Vol 1507 ◽  
Author(s):  
Ryosuke Yamauchi ◽  
Geng Tan ◽  
Daishi Shiojiri ◽  
Nobuo Tsuchimine ◽  
Koji Koyama ◽  
...  

ABSTRACTWe examined the influence of momentary annealing on the nanoscale surface morphology of NiO(111) epitaxial thin films deposited on atomically stepped sapphire (0001) substrates at room temperature in O2 at 1.3 × 10−3 and 1.3 × 10−6 Pa using a pulsed laser deposition (PLD) technique. The NiO films have atomically flat surfaces (RMS roughness: approximately 0.1–0.2 nm) reflecting the step-and-terrace structures of the substrates, regardless of the O2 deposition pressure. After rapid thermal annealing (RTA) of the NiO(111) epitaxial film deposited at 1.3 × 10−3 Pa O2, a periodic straight nanogroove array related to the atomic steps of the substrate was formed on the film surface for 60 s. In contrast, the fabrication of a transient state in the nanogroove array formation was achieved with RTA of less than 1 s. However, when the O2 atmosphere during PLD was 1.3 × 10−6 Pa, random crystal growth was observed and resulted in a disordered rough surface nanostructure after RTA.


1999 ◽  
Vol 574 ◽  
Author(s):  
D. Kumar ◽  
K. G. Cho ◽  
Zhang Chen ◽  
V. Craciun ◽  
P. H. Holloway ◽  
...  

AbstractThe growth, structural and cathodoluminescent (CL) properties of europium activated yttrium oxide (Eu:Y2O3) thin films are reported. The Eu:Y2O3 films were grown in-situ using a pulsed laser deposition technique. Our results show that Eu:Y2O3 films can grow epitaxially on (100) LaAlO3 substrates under optimized deposition parameters. The epitaxial growth of Eu:Y2O3 films on LaAlO3, which has a lattice mismatch of ∼ 60 %, is explained by matching of the atom positions in the lattices of the film and the substrate after a rotation. CL data from these films are consistent with highly crystalline Eu:Y2O3 films with an intense CL emission at 611 nm.


2004 ◽  
Vol 819 ◽  
Author(s):  
Xu Wang ◽  
Yan Xin ◽  
Hanoh Lee ◽  
Patricia A. Stampe ◽  
Robin J. Kennedy ◽  
...  

AbstractBulk Ca2RuO4 is an antiferromagnetic Mott insulator with the metal-insulator transition above room temperature, and the Neel temperature at 113 K. There is strong coupling between crystal structures and magnetic, electronic phase transitions in this system. It exhibits high sensitivity to chemical doping and pressure that makes it very interesting material to study. We have epitaxially grown Ca2RuO4 thin films on LaAlO3 substrates by pulsed laser deposition technique. Growth conditions such as substrate temperature and O2 pressure were systematically varied in order to achieve high quality single-phase film. Crystalline quality and orientation of these films were characterized by X-ray diffractometry. Microstructure of the thin films was examined by transmission electron microscopy. The electrical transport properties were also measured and compared with bulk single crystal.


2018 ◽  
Vol 9 ◽  
pp. 686-692 ◽  
Author(s):  
Daiki Katsube ◽  
Hayato Yamashita ◽  
Satoshi Abo ◽  
Masayuki Abe

We have designed and developed a combined system of pulsed laser deposition (PLD) and non-contact atomic force microscopy (NC-AFM) for observations of insulator metal oxide surfaces. With this system, the long-period iterations of sputtering and annealing used in conventional methods for preparing a metal oxide film surface are not required. The performance of the combined system is demonstrated for the preparation and high-resolution NC-AFM imaging of atomically flat thin films of anatase TiO2(001) and LaAlO3(100).


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