研究目的
Investigating the possibility to obtain chromium boride ?lms in vacuum by ablating a target formed by mixed powders of boron and chromium utilizing an ultra short pulse laser.
研究成果
The study successfully demonstrated the deposition of chromium diboride-rich thin films using ultra-short pulsed laser ablation, with crystalline films obtained only at a substrate temperature of 500°C. The films exhibited a hardness of 21 ± 4 GPa, attributed to their nanocrystalline nature. The deposition mechanism was found to involve gas phase condensation on the substrate surface rather than nanoparticle coalescence.
研究不足
The study was limited by the preferential loss of boron during the ablation-deposition process, requiring the use of a boron-rich target to achieve desired film compositions. Additionally, the formation of crystalline chromium diboride was only achieved at a substrate temperature of 500°C.
1：Experimental Design and Method Selection:
The study utilized pulsed laser deposition (PLD) with a frequency doubled Nd:glass laser (250 fs pulse duration) to deposit chromium diboride-rich thin films in vacuum. The films were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. Hardness was measured by Vickers indentation technique.
2：Sample Selection and Data Sources:
Films were deposited on n-type Si (100) substrates using targets with B/Cr molar ratios of 2:1 and 4:
3：List of Experimental Equipment and Materials:
Equipment included a frequency doubled Nd:glass laser, X-ray diffractometer, X-ray photoelectron spectrometer, scanning electron microscope, transmission electron microscope, and Vickers micro-hardness apparatus.
4：Experimental Procedures and Operational Workflow:
Films were deposited at substrate temperatures ranging from 25 to 500°C. The laser fluence was kept at 2.8 J·cm?2 with a deposition time of 2 hours for all films.
5：8 J·cm?2 with a deposition time of 2 hours for all films.
Data Analysis Methods:
5. Data Analysis Methods: Data analysis involved fitting XPS spectra, calculating hardness from indentation measurements, and analyzing plasma emission spectra.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
