Cathodoluminescence of Praseodymium doped AlN, GaN and turbo static BN.

2004 ◽  
Vol 831 ◽  
Author(s):  
Muhammad Maqbool ◽  
H. H. Richardson ◽  
M. E. Kordesch

ABSTRACTPraseodymium (Pr) doped aluminum nitride (AlN), gallium nitride (GaN) and boron nitride (BN) thin films deposited on Si (111) substrate are studied with cathodoluminescence. AlN:Pr and GaN:Pr films are deposited at 77 K and room temperature respectively while BN:Pr films at 750 K by reactive sputtering, using 100–200 Watts RF power, 5–10 mTorr nitrogen. Metal targets of Al and B with Pr and a liquid target of Ga with solid Pr are used. The dominant peaks observed in the visible range result from 3P0 → 3H4, 3P1→ 3H5, and 3P0 → 3F2 transitions in AlN:Pr, 3P0 → 3H4, 3P0 → 3H6, and 3P0 → 3F2 transitions in GaN:Pr and from 3P0 → 3H4, 3P1→ 3H5, 3P0 → 3H6, and 3P0 → 3F2 transitions in BN:Pr. Additional peaks are observed from AlN:Pr at 335 nm and 385 nm from 1S0 → 1D2 and 1S0 → 1I6 which are not observed in GaN:Pr and BN:Pr films.

2007 ◽  
Vol 124-126 ◽  
pp. 119-122 ◽  
Author(s):  
Chang Sik Son ◽  
Jae Sung Hur ◽  
Byoung Hoon Lee ◽  
Sang Yul Back ◽  
Jeong Seop Lee ◽  
...  

Multi-component ZnO-In2O3-SnO2 thin films have been prepared by RF magnetron co-sputtering using targets composed of In4Sn3O12(99.99%) [1] and ZnO(99.99%) at room temperature. In4Sn3O12 contains less In than commercial ITO, so that it lowers cost. Working pressure was held at 3 mtorr flowing Ar gas 20 sccm and sputtering time was 30 min. RF power ratio [RF1 / ( RF1 + RF2 )] of two guns in sputtering system was varied from 0 to 1. Each RF power was varied 0~100W respectively. The thicknesses of the films were 350~650nm. The composition concentrations of the each film were measured with EPMA and AES. The low resistivity of 1-2 × 10-3 and an average transmittance above 80% in the visible range were attained for the films over a range of δ (0.3 ≤ δ ≤ 0.5). The films also showed a high chemical stability with time and a good uniformity.


Author(s):  
S.K. Streiffer ◽  
C.B. Eom ◽  
J.C. Bravman ◽  
T.H. Geballet

The study of very thin (<15 nm) YBa2Cu3O7−δ (YBCO) films is necessary both for investigating the nucleation and growth of films of this material and for achieving a better understanding of multilayer structures incorporating such thin YBCO regions. We have used transmission electron microscopy to examine ultra-thin films grown on MgO substrates by single-target, off-axis magnetron sputtering; details of the deposition process have been reported elsewhere. Briefly, polished MgO substrates were attached to a block placed at 90° to the sputtering target and heated to 650 °C. The sputtering was performed in 10 mtorr oxygen and 40 mtorr argon with an rf power of 125 watts. After deposition, the chamber was vented to 500 torr oxygen and allowed to cool to room temperature. Because of YBCO’s susceptibility to environmental degradation and oxygen loss, the technique of Xi, et al. was followed and a protective overlayer of amorphous YBCO was deposited on the just-grown films.


2012 ◽  
Vol 526 ◽  
pp. 221-224 ◽  
Author(s):  
A. Amaral ◽  
P. Brogueira ◽  
O. Conde ◽  
G. Lavareda ◽  
C. Nunes de Carvalho

2006 ◽  
Vol 957 ◽  
Author(s):  
Luis Manuel Angelats ◽  
Maharaj S Tomar ◽  
Rahul Singhal ◽  
Oscar P Perez ◽  
Hector J Jimenez ◽  
...  

ABSTRACTZn0.90Co0.10O and Zn0.85[Co0.50Fe0.50]0.15O targets were used to grow thin films by rf magnetron sputtering. XRD patterns of the films showed a strong preferred orientation along c-axis. Zn0.90Co0.10O film showed a transmittance above 75% in the visible range, while the transmittance of the Zn0.85[Co0.50Fe0.50]0.15O film was about 45%; with three absorption peaks attributed to d-d transitions of tetrahedrally coordinated Co2+. The band gap values for Zn0.90Co0.10O and Zn0.85[Co0.50Fe0.50]0.15O films were 2.95 and 2.70 eV respectively, which are slightly less than ZnO bulk. The Zn0.90Co0.10O film showed a relatively large positive magnetoresistance (MR) at the high magnetic field in the temperature range from 7 to 50 K, which reached 11.9% a 7K for the magnetoresistance. The lowest MR was found at 100 K. From M-H curve measured at room temperature shown a probable antiferromagnetic behavior, although was possible to observe little coercive field of 30 Oe and 40 Oe for Zn0.90Co0.10O and Zn0.85[Co0.50Fe0.50]0.15O films, respectively.


1999 ◽  
Vol 572 ◽  
Author(s):  
C. M. Lueng ◽  
H. L. W. Chan ◽  
W. K. Fong ◽  
C. Surya ◽  
C. L. Choy

ABSTRACTAluminum nitride (AlN) and gallium nitride (GaN) thin films have potential uses in high temperature, high frequency (e.g. microwave) acoustic devices. In this work, the piezoelectric coefficients of wurtzite AlN and GaN/AlN composite film grown on silicon substrates by molecular beam epitaxy were measured by a Mach-Zehnder type heterodyne interferometer. The effects of the substrate on the measured coefficients are discussed.


1992 ◽  
Vol 242 ◽  
Author(s):  
T.D. Moustakas ◽  
T. Lei ◽  
R. J. Molnar ◽  
C. Fountzoulas ◽  
E.J. Oles

ABSTRACTTetrahedrally coordinated phases of boron nitride (c-BN and w-BN) were produced by reactive sputtering. The structure of the films was investigated by XRD and TEM diffraction, and found to be poly cry stalline. Films with microhardness up to 3500kg/mm2 were deposited but some degradation over time has been observed. A model for the stabilization of the tetrahedral phases over the graphitic one is proposed.


1978 ◽  
Vol 32 (4) ◽  
pp. 252-253 ◽  
Author(s):  
T. Hariu ◽  
T. Usuba ◽  
H. Adachi ◽  
Y. Shibata

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