Measurements of resistivity of nitrogen-doped single crystals of type Ib diamond by the var der Pauw method with Ti–Pt contacts in the temperature range 573–1000 K

The electrical resistivity values of square diamond plates doped with nitrogen in the form of C-centers with concentrations of 5; 55; 140 ppm are measured by the van der Pauw method in the temperature range of 573–1000 K. Based on the results of the analysis of the primary measurement data, the resistivity values are calculated in the approximation of point ohmic Ti–Pt contacts, as well as taking into account the actual dimensions of triangular angular contacts. It was found that up to the temperature limit of 930 $\pm$ 50 K the differences in the resistivity values obtained by three different methods of the experimental data analysis do not exceed 3–7%. Ti–Pt contacts may be used in microelectronic and quantum optoelectronic devices based on nitrogen-doped diamonds.