Structural Characterization of Pulsed Laser Deposited Ktn Thin Films

1998 ◽  
Vol 541 ◽  
Author(s):  
A. A. Savvinov ◽  
I. G. Siny ◽  
R. S. Katiyar ◽  
M. Pumarol ◽  
H. A. Mourad ◽  
...  

AbstractThe renewed interest in KTa1−xNbxO (KTN) mixed perovskite materials, especially in thin films of a high quality, is connected with their remarkable dielectric properties in the dilute compositions. Off-center Nb ions in the highly polarizable KTaO3 lattice provide a drastic increase in the dielectric peak up to 20 times in comparison with pure KTaO3 and KNbO3. We prepared KTN thin films with several Nb concentrations in the range of 0 ≤ x ≤ 1 by pulsed laser deposition from semented KTaO3, KNbO3 and KNO3 targets. The effect of the substrate and symmetry-breaking defects was studied by micro-Raman spectroscopy. An anomalous residual intensity of the forbidden first-order scattering modes in the cubic paraelectric phase of the KTN films was connected with the formation of polar microregions even far above the bulk Tc value. On the whole, the KTN film behavior shows the existence of specific defects enlarging the perovskite unit cell in the film so that the activity of off-center Nb ions increases in producing larger electric dipoles and extending the precursor phase above Tc.

2021 ◽  
Vol 127 ◽  
pp. 105716
Author(s):  
Tianzhen Guo ◽  
Dan Wang ◽  
Yajun Yang ◽  
Xiaoyong Xiong ◽  
Kelin Li ◽  
...  

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.


2011 ◽  
Vol 257 (15) ◽  
pp. 6445-6450 ◽  
Author(s):  
K. Siraj ◽  
M. Khaleeq-ur-Rahman ◽  
M.S. Rafique ◽  
M.Z. Munawar ◽  
S. Naseem ◽  
...  

1997 ◽  
Vol 109-110 ◽  
pp. 359-361 ◽  
Author(s):  
J.C. Alonso ◽  
R. Diamant ◽  
E. Haro-Poniatowski ◽  
M. Fernández-Guasti ◽  
G. Muñoz ◽  
...  

1994 ◽  
Vol 48 (6) ◽  
pp. 733-736 ◽  
Author(s):  
N. T. McDevitt ◽  
J. S. Zabinski ◽  
M. S. Donley ◽  
J. E. Bultman

Crystalline disorder in thin films plays an important role in determining their properties. Disorder in the crystal structure of MoS2 films prepared by magnetron sputtering and pulsed laser deposition was evaluated with the use of Raman spectroscopy. The peak positions and bandwidths of the first-order Raman bands, in the region 100 to 500 cm−1, were used as a measure of crystalline order. In addition, a low-frequency feature was observed at 223 cm−1 that is not part of the normal first-order spectrum of a fully crystalline specimen. Data presented here demonstrate that this band is characteristic of crystalline disorder, and its intensity depends on the annealing history of the film. This behavior seems to be analogous to the disorder found in graphite thin films.


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