TY - JOUR
T1 - Molecular beam epitaxy growth of superconducting LiFeAs film on SrTiO3(001) substrate
AU - Chang, K.
AU - Deng, P.
AU - Zhang, T.
AU - Lin, H. C.
AU - Zhao, K.
AU - Ji, S. H.
AU - Wang, L. L.
AU - He, K.
AU - Ma, X. C.
AU - Chen, X.
AU - Xue, Q. K.
N1 - Publisher Copyright:
Copyright © EPLA 2015.
PY - 2015/1/1
Y1 - 2015/1/1
N2 - The stoichiometric "111" iron-based superconductor, LiFeAs, has attacted great research interest in recent years. For the first time, we have successfully grown a LiFeAs thin film by molecular beam epitaxy (MBE) on a SrTiO3(001) substrate, and studied the interfacial growth behavior by reflection high-energy electron diffraction (RHEED) and low-temperature scanning tunneling microscope (LT-STM). The effects of substrate temperature and Li/Fe flux ratio were investigated. A uniform LiFeAs film as thin as 3 quintuple layers (QL) is formed. A superconducting gap appears in LiFeAs films thicker than 4 QL at 4.7 K. When the film is thicker than 13 QL, the superconducting gap determined by the distance between the coherence peaks is about 7 meV, close to the value of bulk material. The ex situ transport measurement of a thick LiFeAs film shows a sharp superconducting transition around 16 K. The upper critical field, Hc2(0) = 13.0T, is estimated from the temperature-dependent magnetoresistance. The precise thickness and quality control of the LiFeAs film paves the road for growing similar ultrathin iron arsenide films.
AB - The stoichiometric "111" iron-based superconductor, LiFeAs, has attacted great research interest in recent years. For the first time, we have successfully grown a LiFeAs thin film by molecular beam epitaxy (MBE) on a SrTiO3(001) substrate, and studied the interfacial growth behavior by reflection high-energy electron diffraction (RHEED) and low-temperature scanning tunneling microscope (LT-STM). The effects of substrate temperature and Li/Fe flux ratio were investigated. A uniform LiFeAs film as thin as 3 quintuple layers (QL) is formed. A superconducting gap appears in LiFeAs films thicker than 4 QL at 4.7 K. When the film is thicker than 13 QL, the superconducting gap determined by the distance between the coherence peaks is about 7 meV, close to the value of bulk material. The ex situ transport measurement of a thick LiFeAs film shows a sharp superconducting transition around 16 K. The upper critical field, Hc2(0) = 13.0T, is estimated from the temperature-dependent magnetoresistance. The precise thickness and quality control of the LiFeAs film paves the road for growing similar ultrathin iron arsenide films.
UR - https://www.scopus.com/pages/publications/84922422834
U2 - 10.1209/0295-5075/109/28003
DO - 10.1209/0295-5075/109/28003
M3 - Article
AN - SCOPUS:84922422834
SN - 0295-5075
VL - 109
JO - EPL
JF - EPL
IS - 2
M1 - 28003
ER -