Search

In magnetron sputtering systems, lead-zirconium-titanium oxide (PbZr1−xTixO3 or PZT) thin films were prepared in a mixture atmosphere of Ar and O2 with various oxygen partial pressures (0, 0.5, 1, 1.5 and 2% oxygen). About 600 nm PZT ferroelectric thin films were deposited on substrates, and then annealed at 600°C for 35 s. The structural, electrical and ferroelectric properties of PZT films were studied. As the oxygen partial pressure increased, the remanent polarisation rose first and went down later, and the leakage current density decreased first and then increased. At the oxygen partial pressure of 0.5%, we obtained the largest remanent polarisation and the minimum leakage current density. The XRD diffraction spectrum of all films displayed predominant (111) preferred orientation, and there was a weak XRD diffraction peak of pyrochlore phase in the PZT films deposited in pure Ar.

Threshold ion-pair production spectroscopy (TIPPS) has been applied to two isotopomers, HCl and DCl. From the high-resolution TIPP spectra the ion-pair thresholds of the two molecules have been precisely measured. Combined with the known ionization energy of H(D) and the electron affinity of Cl, the difference between their bond dissociation energies is calculated, and therefore an experimental determination of the effect of Born–Oppenheimer breakdown on the dissociation limit of the ground state potential curve has been obtained. The difference in De for the two isotopomers was found to be: De(H–Cl)−De(D–Cl)=3.2±1.0 cm−1. The bond energy for HCl was in agreement with our previous determination, D0(H–Cl)=35748.2±0.8 cm−1. These results are compared to a recent study of Born–Oppenheimer breakdown in HCl by Coxon and Hajigeorgiou, where high resolution spectroscopic data was used to fit Born–Oppenheimer breakdown correction terms for the intramolecular potential function. The present study also measured the high resolution spectra for photoion-pair production for HCl and DCl in the threshold region for ion-pair production (∼86 nm). Although there is qualitative agreement between the current results and previous experimental and theoretical work, there are some important differences. The possible mechanism for ion-pair formation in HCl and DCl is discussed in light of these high resolution results.

The spectroscopic technique of threshold ion-pair production spectroscopy (TIPPS) has been applied to the triatomic molecule HCN. We have recorded the total ion-pair yield and TIPP spectra for the HCN-->H(+) + CN(-) process using coherent vacuum ultraviolet excitation. From the simulation of our high-resolution TIPP spectrum we have precisely measured the HCN ion-pair threshold E(IP) (0) to be 122 244 +/- 4 cm(-1). This value could be used to determine the bond dissociation energy D(0)(H-CN) to unprecedented accuracy. Our fitting result also showed that rotationally excited instead of cold CN(-) fragment is favored as the ion-pair dissociation product in the threshold region.