Visible-ultraviolet spectroscopic ellipsometry of lead zirconate titanate thin films

We measured pseudodielectric functions in the visible-ultraviolet spectral range of Pb(ZrxTi1−x)O3 (x=0.2, 0.56, 0.82) (PZT)grown on platinized silicon substrate using the sol-gel method and also on (0001) sapphire using radio frequency sputtering method. Using a parametric optical constant model, we estimated the dielectric functions of the PZTthin films. Taking the second derivative of the fitted layer dielectric functions and using the standard critical point model, we determined the parameters of the critical points. In the second derivative spectra, the lowest bandgap energy peak near 4eV is fitted as a double peak for annealedPZTs associated with the perovskite phase. As-grown PZTs have mainly pyrochlore phase and the lowest bandgap is fitted as a single peak. We compared the bandgap energies with literature values

DAOA Variants on Diagnosis and Response to Treatment in Patients with Major Depressive Disorder and Bipolar Disorder

OBJECTIVE: This study investigated whether selected D-amino acid oxidase activator ( DAOA) gene single nucleotide polymorphisms (SNPs; rs3916966, rs3916967, rs2391191, rs3916968, rs7139958, rs9558571, rs778293) are associated with major depressive disorder (MDD) and bipolar disorder (BD), and whether they can predict clinical outcomes in Korean in-patients treated with antidepressants and mood stabilizers, respectively. METHODS: In total, 145 patients with MDD, 132 patients with BD and 170 psychiatrically healthy controls were genotyped for the DAOA SNPs. Baseline and final clinical assessments included the Montgomery—Asberg Depression Rating Scale and Young Mania Rating Scale for patients with MDD and BD, respectively. RESULTS: There was no association between DAOA SNP genotypes or alleles with diagnosis, clinical improvement, response rates or remission rates for MDD and BD. Haplotype analyses found no association with MDD or BD diagnosis or clinical outcomes. CONCLUSIONS: The findings suggest that the DAOA SNPs investigated may not affect MDD or BD phenotype, clinical symptoms or other clinical factors, and are unlikely to be involved in MDD or BD development and treatment outcomes. Given the study's limitations, further investigation should be carried out

Fabrication and current-voltage characterization of a ferroelectric lead zirconate titanate/AlGaN∕GaN field effect transistor

We demonstrated ferroelectricfield effect transistors (FFETs) with hysteretic I-V characteristics in a modulation-doped field effect transistors(MODFET)AlGaN∕GaN platform with ferroelectricPb(Zr,Ti)O3 between a GaN channel and a gate metal. The pinch-off voltage was about 6–7V comparable to that of conventional Schottky gate MODFET. Counterclockwise hysteresis appeared in the transfer characteristics with a drain current shift of ∼5mA for zero gate-to-source voltage. This direction is opposite and much more pronounced than the defect induced clockwise hysteresis in conventional devices, which suggests that the key factor contributing to the counterclockwise hysteresis of the FFET is the ferroelectric switching effect of the lead zirconate titanate gate