摘要:

High quality diamond films have been deposited on tantalum nitride (TaN2) materials, which are used as heating elements for high‐speed thermal printing heads, by using the microwave plasma chemical vapor deposition technique via a particular pretreatment, intercurrent treatment, and shutdown process. Scanning electron microscopy, x‐ray diffraction, and Raman spectroscopy were employed to investigate the structure and quality of the films. A highly adherent film‐substrate system was obtained. The possibility of chemical vapor deposition diamond films being used as protective layers of thermal printing heads is indicated. The low‐temperature pretreatment with a methane‐rich hydrogen plasma plays an important role in nucleating diamond crystallites on the TaN2substrate, thus enhancing the nucleation density and making it possible to form a continuous diamond film on TaN2. A speculation is proposed to interpret the effect. ©1995 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.360394

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The heat capacity of the ternary compounds RNiGe(R=Er, Dy, Gd, and Y) was studied in the temperature range between 2 and 40 K. From the heat capacity curves, Ne´el temperatures are found to be 3.3, 7.4, and 10.7 K for ErNiGe, DyNiGe, and GdNiGe, respectively. The heat capacity of YNiGe was well fitted with an average Debye temperature of 272 K in the temperature range between 2 and 40 K. The changes of magnetic entropy indicate a strong influence of the crystal field on the Er+3and Dy+3ion in ErNiGe and DyNiGe compounds. These results suggest the possibility of using these compounds as magnetic regenerator materials near the temperature of 4.2 K. ©1995 American Institute of Physics. 

ISSN:0021-8979    

DOI:10.1063/1.360395

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

A concise and general solution is derived for the exact effective moduli of a two‐phase medium for multifield, coupled linear responses, in which the medium is insensitive to phase interchange. The constituents are isotropic and statistically symmetric. The solutions follow from a compatibility condition together with a phase interchange theorem recently discovered by Milgrom and Shtrikman [Phys. Rev. A40, 1568 (1989)]. Due to the mathematical analogy, the obtained results are applicable to certain classes of two‐dimensional polycrystals. The solution extends the corresponding results for two‐coupled field media obtained by Benveniste [J. Mech. Phys. Solids43, 553 (1995)]. ©1995 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.360396

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Carbon nitride films were synthesized on Si(100) substrate using relatively high‐pressure radio‐frequency magnetron sputtering of a graphite target in a nitrogen ambient. The influences of the substrate temperature and pressure on deposition rate and the film composition ratio N/C and C–N bonding were investigated using x‐ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR). The deposition rate had a maximum in the investigated pressure region and reduced as the substrate temperature increased. XPS spectra showed that the deposited films were very large N/C value up to 1.20, and unchanged after thermal treatment up to about 900 K, the latter confirmed by FTIR. ©1995 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.360397

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

Thermally induced reactions in TiN/Al–Cu/TiN have been investigated. It is observed that the amount of the reactions is different at the two interfaces between Al–Cu and TiN. While there is minimal reaction between Al–Cu and the TiN overlayer, the reaction between Al–Cu and the TiN underlayer increases the sheet resistance of Al–Cu by as much as 15%. It is further shown that the asymmetric reactions are most likely caused by the different degree of (111) texture of TiN grown on amorphous SiO2and textured, polycrystalline Al–Cu. ©1995 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.360398

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

The sidegating effect on the Schottky barrier in ion‐implanted GaAs was investigated with capacitance‐voltage profiling at various negative substrate voltages. It was demonstrated that the negative substrate voltage modulates the Schottky depletion region width as well as the space charge region at the substrate‐active channel interface. ©1995 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.360399

出版商:AIP    

年代:1995

数据来源: AIP

摘要:

We report on the room temperature optical characterization of single crystal hexagonal GaN films on (0001) sapphire grown by metalorganic chemical vapor deposition. The energy gap of GaN was determined to be 3.400 eV by photoreflectance and the possible origin of the photoreflectance signal is discussed. Photocurrent measurement exhibited a peak at 3.351 eV and a continued photoresponse through the ultraviolet region. We found that the intensity of photocurrent was dependent upon the chopper frequency in the measurement. Absorption coefficient and film thickness were obtained from the optical transmission spectra. ©1995 American Institute of Physics.

ISSN:0021-8979    

DOI:10.1063/1.360400

出版商:AIP    

年代:1995

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.360788

出版商:AIP    

年代:1995

数据来源: AIP