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This work relates to the field of thermophysical parameters of refractory interstitial alloys. The isochoric heat capacity of cubic titanium carbide TiCx has been calculated within the Debye approximation in the carbon concentration  range x = 0.70–0.97 at room temperature (300 K) and at liquid nitrogen temperature (80 K) through the Debye temperature established on the basis of neutron diffraction analysis data. It has been found out that at room temperature with decrease of carbon concentration the heat capacity significantly increases from 29.40 J/mol·K to 34.20 J/mol·K, and at T = 80 K – from 3.08 J/mol·K to 8.20 J/mol·K. The work analyzes the literature data and gives the results of the evaluation of the high-temperature dependence of the heat capacity СV of the cubic titanium carbide TiC0.97 based on the data of neutron structural analysis. It has been proposed to amend in the Neumann–Kopp formula to describe the high-temperature dependence of the titanium carbide heat capacity. After the amendment, the Neumann–Kopp formula describes the results of well-known experiments on the high-temperature dependence of the heat capacity of the titanium carbide TiCx. The proposed formula takes into account the degree of thermal excitation (a quantized number) that increases in steps with increasing temperature.The results allow us to predict the thermodynamic characteristics of titanium carbide in the temperature range of 300–3000 K and can be useful for materials scientists.

The relaxation kinetics of photoconductivity in neutron-doped silicon (NDS) of the p-type is discussed. It is found that the relaxation process in the compensated p-Si differs from that in the reference p-Si sample. The difference is explained on the basis of concept of different micrononuniformity of the material conductivity. A method based on studying the dependences of charge-carrier mobility on annealing time is developed for determining thermal annealing of structural defects.Silicon is known as a semiconductor material most extensively employed in electronics, which imposes stringent requirements upon its properties and characteristics. In particular, accumulation of thermal and radiation defects in silicon in most cases results in the occurrence of compensating centers. If the concentration of these centers becomes comparable with the initial charge-carrier concentration, electrophysical and photoelectrical properties of the material undergo significant changes. The majority of researchers [1, 2] believe that the photoelectrical properties of the compensated material depend on the type of impurity centers. Other researchers [3][4][5] consider that these properties mainly depend on the potential barriers between high-resistance and low-resistance regions. In so doing, the effect of the deep impurity centers and potential barriers between the p -and p + (or n -and n + )-regions on the electrophysical properties of the material is poorly understood.This work is aimed at studying the effect of conductivity micrononuniformity on the conductivity kinetics in silicon compensated by phosphorous atoms.Silicon of the р-type with ρ = 1-100 Ω⋅cm was used as an initial material. Silicon was doped with phosphorous impurity (P) using a nuclear reaction 30 Si (n, γ) 31 Si → 31 P +β − (NDS) in a VVR-SM nuclear reactor at the thermal neutron intensity ∼1⋅10 14 cm -2 [6]. In this case, the concentration of introduced phosphorous can be calculated by the following formula:where Ф = I·t is the flux of slow neutrons, cm -2 , I is the flux density of slow neutrons, cm -2 ⋅s -1 , and t is the irradiation time, s. Radiation defect annealing performed at a temperature of ∼1270 K in the air during ∼30 min was followed by slow cooling at the rate 5-10 deg/min. Ohmic contacts were produced by soldering an Sn+In (50 + 50%) alloy to р-Si at ∼400 K. The electrophysical parameters of doped silicon are summarized in Table 1.