摘要:

The sputter deposition of highly ⟨100+001⟩‐textured tetragonal BaTiO3on unheated substrates using a pressed powder BaTiO3target and a radio frequency‐excited Ne discharge is reported. For comparison, amorphous BaTiO3was also produced, using an Ar discharge operated at the same value of all other independent process parameters.Insitudischarge diagnostics using optical emission spectrometry was used to study the plasma volume. Data show that there was atomic Ti but no atomic Ba in the Ne discharge used to producet‐BaTiO3. However, both atomic Ba and Ti were identified in the Ar discharge used to producea‐BaTiO3. A probable source of free Ba atoms in the plasma is the reduction of BaTiO3at the target surface due to the sputtering action of Ar+ions. By comparison with other sputter‐deposited metal oxide systems, the effect on film crystallinity of atomic metal versus molecular metal oxide flux incident on the substrate is discussed.

ISSN:0021-8979    

DOI:10.1063/1.350991

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

We present a new procedure to obtain the anisotropy distribution in a ferromagnetic amorphous alloy. The method is based on the existence of second‐order harmonics in the differential magnetization around the anisotropy field. We derive a mathematical expression relating the strength of the second‐harmonic component and the anisotropy distribution function. An experimental setup is described and the optimum operating conditions discussed. The apparatus is based on the detection of the voltage induced in a coil using a lock‐in amplifier tuned to a frequency double to the exciting one. Results obtained on a stress annealed sample show the existence of well defined values of the anisotropy in addition to a continuous background.

ISSN:0021-8979    

DOI:10.1063/1.350992

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

We studied the initial layer of GaAs films grown on Si substrates by a two‐step metalorganic chemical vapor deposition method, in which an initial GaAs layer is grown on a Si substrate at low temperature. It was found that the V/III ratio during the growth of the initial layer plays a key role in improving the quality of GaAs film on a Si substrate. The initial GaAs layer grows two dimensionally as a continuous film when it is grown at a low V/III ratio.

ISSN:0021-8979    

DOI:10.1063/1.350993

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

The paper presents a technique for identifying and removing unwanted terms in the field power expansion of multipolar magnets. The technique is based on the measurement of the radial field at the poles of the magnet. The field terms are derived by analytical formulas and used to evaluate the current corrections. This trimming procedure has been tested for a 16‐pole magnet designed for electron paramagnetic resonance imaging and permits a continuous control of the field configuration.

ISSN:0021-8979    

DOI:10.1063/1.350994

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

The transverse‐optical (TO) phonon mode in a CdS film with a thickness less than 410 A˚ is observed at 4880 A˚ excitation wavelength which is above the band gap of CdS bulk (2.42 eV) at room temperature. This phenomenon is ascribed to the size quantization of the free carrier in the low‐dimensional thin‐film structure. The quantum size effect causes a blue shift of the band gap in the as‐deposited CdS thin film. The Raman shift of the TO mode of CdS film is around 220 cm−1. The softening energy of the TO phonon mode is about 8 cm−1. It was found that this softening energy is independent of the film thickness.

ISSN:0021-8979    

DOI:10.1063/1.350995

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

The premise for the basic approximation made by the authors of the subject paper is scrutinized.

ISSN:0021-8979    

DOI:10.1063/1.350996

出版商:AIP    

年代:1992

数据来源: AIP

摘要:

We acknowledge this most recent comment and several previous comments by the same author on our work during the past six months. This comment concerns a different problem than the one considered in our paper and is characterized by scientific shortcomings. We stand by all statements in the original paper.

ISSN:0021-8979    

DOI:10.1063/1.350997

出版商:AIP    

年代:1992

数据来源: AIP

ISSN:0021-8979    

DOI:10.1063/1.350998

出版商:AIP    

年代:1992

数据来源: AIP