Researchers studying the electrical properties of cubic boron nitride (cBN) films on diamond substrates encounter several challenges. One major issue is achieving high-quality deposition of cBN films onto diamond substrates with minimal defects and interface roughness. This challenge arises due to the differences in lattice constants and thermal expansion coefficients between cBN and diamond, leading to stress-induced defects and mismatches during the deposition process. Taking these setbacks into consideration, how can I measure the resistivity of this nanomaterial using a four-point probe method?