Semi-Epitaxial SmB₆ Thin Films Prepared by the Molecular Beam Epitaxy

详细信息    查看全文

• 作者：Hiroaki Shishido^a ; ^b ; ^{shishido@pe.osakafu-u.ac.jp" class="auth_mail" title="E-mail the corresponding author} ; Yutaka Yoneda^a ; Takuya Yoshida^a ; Satoru Noguchi^a ; ^b ; ^c ; Takekazu Ishida^a ; ^b
• 关键词：Kondo insulator ; SmB6 ; thin film growth
• 刊名：Physics Procedia
• 出版年：2015
• 出版时间：2015
• 年：2015
• 卷：75
• 期：Complete
• 页码：405-412
• 全文大小：479 K

文摘

We grow thin films of SmB6 by molecular beam epitaxy under ultra-high vacuum better than 1×10−6 Pa. Sm and B were evaporated independently by Knudsen cells with the deposition rate ratio of B and Sm as B/Sm in between 4.0 and 5.7 on an MgO (100) substrate with the substrate temperature of 1000 ∘C. Reflection high energy electron diffraction patterns show spotted ones indicating a relatively flat film surfaces. This is in good agreement with the surface roughness measured by the atomic force microscope. Interplane and inplane X-ray diffraction measurements represent the preference growth of c-axis oriented SmB4 thin films with the ratio B/Sm = 4.0. We obtained SmB6 thin films with the ratio B/Sm in between 4.9 and 5.7. X-ray diffraction measurements clarify that our SmB6 thin films show evidence of partial epitaxial growth as major domains orienting along [100]SmB6 ∥ [100]MgO. Crystallinity of inplane alignment is improved with approaching the stoichiometric deposition rate of B/Sm = 6. The electrical resistivity increases with decreasing temperature as a semiconductor, and becomes constant at low temperatures. These features well reproduce the tendency observed for the resistivity of bulk samples.