Oleg S. Kudryavtsev

High‐Pressure Synthesis of Boron‐Doped Ultrasmall Diamonds from an Organic Compound

The first application of the high-pressure-high-temperature (HPHT) technique for direct production of doped ultrasmall diamonds starting from a one-component organic precursor is reported. Heavily boron-doped diamond nanoparticles with a size below 10 nm are produced by HPHT treatment of 9-borabicyclo [3,3,1]nonane dimer molecules.

Anomalous enhancement of nanodiamond luminescence upon heating

Characteristic photoluminescence (PL) of nanodiamonds (ND) of different origin (detonation, HPHT, extracted from meteorite) was studied in situ at high temperatures in the range 20–450 °C. Luminescence was excited using 473 nm laser and recorded in the range 500–800 nm. In contrast to decrease of point defect PL in bulk diamond with temperature, we found that the ND luminescence related to ND surface defects increases almost an order of magnitude upon heating to 200–250 °C. The observed effect reveals that water adsorbed on ND surfaces efficiently quenches PL; water desorption on heating leads to dramatic increase of the radiative de-excitation.

The influence of boron doped nanodiamonds on hydrogen bonds in suspensions of protic solvents

This work presents the results of study of the influence of BDND on hydrogen bonds of protonic solvents. In addition, the comparative analysis of the interactions of BDND and DND-COOH with solvents molecules was carried out. The analysis of temperature dependences of the quantitative characteristics of the stretching bands of OH groups of the solvents and the suspensions of NDs has shown that the BDND and DND differently weaken the hydrogen bonds in water and in water-ethanol solution with 70 vol. % ethanol content. In water-ethanol solution with 20 vol. % of ethanol the both NDs practically does not change the network of hydrogen bonds.