Ali Bakhtiar, Xu Han, Chetty Dashavir, Sang Robert T, Litvinyuk Igor V, Rybachuk Maksym
School of Engineering and Built Environment, Griffith University, 170 Kessels Road, Nathan, QLD 4111, Australia.
Centre for Quantum Dynamics and Australian Attosecond Science Facility, Griffith University, Science Road, Nathan, QLD 4111, Australia.
J Phys Chem Lett. 2022 Mar 31;13(12):2679-2685. doi: 10.1021/acs.jpclett.2c00429. Epub 2022 Mar 18.
The degree of laser-induced graphitization from a sp-bonded to a sp-bonded carbon fraction in a single crystal chemical vapor deposited (CVD) diamond under varying fluence of an ultrashort pulsed laser (30 fs, 800 nm, 1 kHz) irradiation has been studied. The tetrahedral CVD sp phase is found to transition to primarily an sp aromatic crystalline graphitic fraction below the critical fluence of 3.9 J/cm, above which predominantly an amorphous carbon is formed. A fractional increase of fluence from 3.3 to 3.9 J/cm (∼20%) results in a substantially (∼3-fold) increased depth of the sp graphitized areas owing to the nonlinear interactions associated with a fs laser irradiation. Additionally, formation of a C═O carbonyl group is observed below the critical threshold fluence; the C═O cleavage occurrs gradually with the increase of irradiation fluence of 30 fs laser light. The implications for these findings on enhancement of fs driven processing of diamonds are discussed.
研究了在超短脉冲激光（30 fs，800 nm，1 kHz）不同能量密度照射下，单晶化学气相沉积（CVD）金刚石中从sp键合碳到sp键合碳组分的激光诱导石墨化程度。发现四面体CVD sp相在低于3.9 J/cm的临界能量密度下主要转变为sp芳香族结晶石墨组分，高于该能量密度则主要形成非晶碳。能量密度从3.3 J/cm增加到3.9 J/cm（约20%）会导致sp石墨化区域的深度大幅增加（约3倍），这是由于与飞秒激光照射相关的非线性相互作用。此外，在临界阈值能量密度以下观察到C═O羰基的形成；随着30 fs激光照射能量密度的增加，C═O键逐渐断裂。讨论了这些发现对增强飞秒驱动的金刚石加工的意义。
