MEASUREMENTS OF ELECTROMAGNETIC SHIELDING EFFECT USING HTSC MATERIALS

1996 ◽  
Vol 10 (07) ◽  
pp. 293-297
Author(s):  
V. VIDYALAL ◽  
K. RAJASREE ◽  
C.P.G. VALLABHAN
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Electromagnetic Shielding ◽  
Shielding Effect ◽  
Aluminium Copper ◽  
Superconducting Ceramics ◽  
Htsc Material ◽  
Set Up

A simple experimental set-up is described to measure the electromagnetic shielding property of high Tc superconducting samples. Measurements were performed using HTSC materials in the form of laser ablated thin films, powders and sintered pellets. Samples used were Gd-123 in pure and doped form as well as a few Bi-based superconducting ceramics. For comparison, similar measurements were carried out on metals like aluminium, copper and μ metal. Very effective shielding was observed for HTSC materials compared to the conventional materials mentioned above. However it also depended on the sample types and poor shielding was observed for powdered HTSC material in comparison to thin films prepared by laser ablation.

Study on Mechanical and Electromagnetic Shielding Properties of Carbon Fibers/Butyl Rubber Composite Films

2011 ◽  
Vol 306-307 ◽  
pp. 848-851 ◽  
Author(s):  
Ri Cheng Yan ◽  
Zheng Hou Zhu ◽  
Hui Song ◽  
Xue Jiao Xu ◽  
Xiao Min Li
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Carbon Fibers ◽  
Testing Machine ◽  
Composite Films ◽  
Electromagnetic Shielding ◽  
Butyl Rubber ◽  
National Standard ◽  
Shielding Effect ◽  
Rubber Composite

The carbon fibers / rubber composite films were fabricated by compression molding method with butyl rubber (IIR) as matrix and carbon fiber as reinforced material. The mechanical properties and electromagnetic shielding effect of the thin films at different conditions were measured by the WDW electronic universal testing machine according the national standard GB13022-91 and the far-field EMC shielding effectiveness test fixture (DN1015 type) respectively. The results show that the good mechanical properties of composite films with mess ratio of IIR and carbon black of 1:6 and vulcanizing time of 1.5h were obtained at the same other condition that the tensile strength reached 534.65MPa, the elongation rate reached 87.26% and the yield point stress up to124.85MPa. Meanwhile, it is also found that the electromagnetic shielding effect of the thin films shows negative growth at low frequency area ranging from 1MHz to 300MHz. Whereas, the shielding effect increases with frequency at 300MHz ~ 1.5GHz, and the SE value is up to -25dB ~-35dB.

Observations on the growth of YBa2Cu3O7-δ thin films on MgO by pulsed-laser ablation

1991 ◽  
Vol 49 ◽  
pp. 1068-1069
Author(s):  
M. Grant Norton ◽  
C. Barry Carter
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Laser Ablation ◽  
Substrate Surface ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Laser Ablation Process ◽  
Deposition Parameters

Pulsed-laser ablation has been widely used to produce high-quality thin films of YBa2Cu3O7-δ on a range of substrate materials. The nonequilibrium nature of the process allows congruent deposition of oxides with complex stoichiometrics. In the high power density regime produced by the UV excimer lasers the ablated species includes a mixture of neutral atoms, molecules and ions. All these species play an important role in thin-film deposition. However, changes in the deposition parameters have been shown to affect the microstructure of thin YBa2Cu3O7-δ films. The formation of metastable configurations is possible because at the low substrate temperatures used, only shortrange rearrangement on the substrate surface can occur. The parameters associated directly with the laser ablation process, those determining the nature of the process, e g. thermal or nonthermal volatilization, have been classified as ‘primary parameters'. Other parameters may also affect the microstructure of the thin film. In this paper, the effects of these ‘secondary parameters' on the microstructure of YBa2Cu3O7-δ films will be discussed. Examples of 'secondary parameters' include the substrate temperature and the oxygen partial pressure during deposition.

Laser ablation of YBCO targets and optical-breakdown-assisted PLD for high T c superconducting thin films deposition

1998 ◽  
Author(s):  
Ileana Apostol ◽  
Razvan Stoian ◽  
C. Luculescu ◽  
Razvan V. Dabu ◽  
Aurel Stratan ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Optical Breakdown ◽  
Superconducting Thin Films

scholarly journals Organic thin films formation by laser ablation.

1993 ◽  
Vol 6 (3) ◽  
pp. 429-432 ◽  
Author(s):  
KENJIN HIGAKI ◽  
CHIAKI NAGAI ◽  
OSAMU MURATA ◽  
HAYAMI ITOH
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Organic Thin Films

Synthesis of Nd-doped Si thin films by laser ablation

2010 ◽  
pp. NA-NA
Author(s):  
Shinji Kawai ◽  
Shuji Komuro ◽  
Toru Katsumata
Keyword(s):  
Thin Films ◽  
Laser Ablation

scholarly journals Preparation and Properties of Superconducting thin Films by Excimer Laser Ablation

1990 ◽  
Vol 191 ◽  
Author(s):  
Michael E. Geusic ◽  
Alan F. Stewart ◽  
Larry R. Pederson ◽  
William J. Weber ◽  
Kenneth R. Marken ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Excimer Laser ◽  
Laser Energy ◽  
Substrate Surface ◽  
Xrd Analysis ◽  
Zero Field ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
Excimer Laser Ablation

ABSTRACTExcimer laser ablation with an in situ heat treatment was used to prepare high quality superconducting YBa2Cu3O7−x thin films on (100)-SrTiO3 and (100)-LaAlO3 substrates. A pulsed excimer laser (XeCl; 308 nm) was used to ablate a rotating, bulk YBa2Cu3O7−x target at a laser energy density of 2–3 J/cm2. Based on four-probe dc resistance measurements, the films exhibited superconducting transition temperatures (Tc, midpoint) of 88 and 87K with 2K (90–10%) transition widths for SrTiO3 and LaAlO3, respectively. Transport critical current densities (Jc) measured at 77K were 2 × 106 and 1 × 106 A/cm2 in zero field for SrTiO3 and LaAlO3, respectively. X-ray diffraction (XRD) analysis showed the films to be highly oriented, with the c-axis perpendicular to the substrate surface.

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