Emission probability measurement of γ-ray of Rh

¹⁰⁵Rh becomes a stable ¹⁰⁵Pd after β⁻-decay with a half-life of 35.36 h. The energies of especially strong γ-rays emitted from ¹⁰⁵Rh are 306.1 and 318.9 keV, and the emission probabilities are evaluated to be 5.1±0.3% and 19.1±0.6% by de Frenne et al. To improve the certainty, the γ-ray emission probabilities were determined from the disintegration rate and absolute γ-ray intensities measured using a 4πβ(ppc)-γ(HPGe) coincidence apparatus with two-dimensional data-acquisition system. The results for the 306.1 and 318.9 keV γ-rays were 4.76±0.05% and 16.99±0.17%, respectively.     

Photoreflectance study of δ-doped semiconductor layers by a fast Fourier transformation

Photoreflectance (PR) spectroscopy has been applied to the investigation of Si δ-doped GaAs, Al_0.35Ga_0.65As and AlAs layers grown by metal–organic vapor phase epitaxy (MOVPE) on GaAs substrates. The observation of Franz–Keldysh oscillations (FKO) and the application of fast Fourier transform (FFT) has allowed us to determine the internal electric field and, hence, the potential barrier between surface and δ-doped region of the layer. The FFT of the photoreflectance spectra has exhibited two separate heavy and light hole frequencies showing that the FKO in the PR signal are always the superposition of these two components.     

Analysis of interface states and series resistance at MIS structure irradiated under Co γ-rays

In this research, we investigated the effect of ⁶⁰Co γ-ray exposure on the electrical properties of Au/SnO₂/n-Si (MIS) structures using current–voltage (I–V) measurements. The fabricated devices were exposed to γ-ray doses ranging from 0 to 300 kGy at a dose rate of 2.12 kGy h⁻¹ in water at room temperature. The density of interface states N_ss as a function of E_c–E_ss is deduced from the forward bias I–V data for each dose by taking into account the bias dependence effective barrier height and series resistance of device at room temperature. Experimental results show that the γ-irradiation gives rise to an increase in the zero bias barrier height Φ_BO, as the ideality factor n and N_ss decrease with increasing radiation dose. In addition, the values of series resistance were determined using Cheung's method. The R_s increases with increasing radiation dose. The results show that the main effect of the radiation is the generation of interface states with energy level within the forbidden band gap at the insulator/semiconductor interface.     

Analysis of ISE in dynamic hardness measurements of β-Sn single crystals using a depth-sensing indentation technique

The dynamic indentation tests on (001) plane β-Sn single crystals having different growth directions under different peak indentation test load (10, 20, 30, 40, and 50 mN) has been investigated. The experimental results reveal that the measured hardness values exhibit a peak-load dependence, i.e., indentation size effect (ISE). Such peak-load dependence is then analyzed using the Meyer's law, the Hays–Kendall's approach, the Elastic/Plastic Deformation model, the Proportional Specimen Resistance (PSR) model, and the Modified PSR (MPSR) model. As a result, Modified PSR model is found to be the most effective for dynamic hardness determination of β-Sn single crystals.