Phase formation of Nb₂AlC investigated by combinatorial thin film synthesis and ab initio calculations

详细信息    查看全文

• 作者：Lin Shang^a ; Moritz to Baben^a ; ^b ; Konda Gokuldoss Pradeep^a ; Stefanie Sandlö ; bes^c ; Marshal Amalraj^a ; Marcus Hans^a ; ^{hans@mch.rwth-aachen.de" class="auth_mail" title="E-mail the corresponding author} ; Keke Chang^a ; Denis Music^a ; Daniel Primetzhofer^d ; Jochen M. Schneider^a
• 关键词：Mn+1AXn phases ; Combinatorial magnetron sputtering ; Ab initio calculations ; Elastic property ; Homogeneity range
• 刊名：Journal of the European Ceramic Society
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：37
• 期：1
• 页码：35-41
• 全文大小：1413 K

文摘

The phase formation of Nb₂AlC was studied by combinatorial thin film synthesis and ab initio calculations. Thin films with lateral chemical composition gradients were synthesized by DC magnetron sputtering at substrate temperatures of 710–870 °C. The lowest formation temperature for Nb₂AlC is between 710 and 750 °C. A predominantly single phase Nb₂AlC region where 99% of the X-ray diffraction intensity originate from Nb₂AlC was identified. Furthermore, selected area electron diffraction analysis reveals the local formation of single phase Nb₂AlC. The limited Al solubility in Nb₂AlC compared with Cr₂AlC can be understood by comparing the defect formation energy of Al substituting Nb and Cr in Nb₂AlC and Cr₂AlC, respectively. This methodology may serve as indicator for the magnitude of the A-element homogeneity range in M_n+1AX_n phases. The structural and elastic properties of Nb₂AlC determined experimentally are in very good agreement with the ab initio calculated data.