Résumé
Hexagonal boron nitride crystals with a single boron isotope (monoisotopic) were produced at atmospheric pressure from a molten metal solution of nickel and chromium. Crystals with both pure 10 B and 11 B were produced. Narrow Raman peaks widths of 3 cm -1 and photoluminescence peaks at 5.75 eV demonstrate the crystals are high quality. The room temperature thermal conductivity of monoisotopic hBN is 40% higher than hBN with the natural distribution of boron, due to a lack of isotopic disorder. Because its phonon lifetimes are more than three times longer that natural hBN, monoisotopic hBN is a better for nanophotonics.