Effects of film thickness on the superconductivity of LaSi2(00l)/Si(100) films

In this paper, we studied the superconducting properties of the LaSi 2 (00 l )/Si(100) single-crystalline thin films prepared by the molecular beam epitaxy (MBE) method with different thicknesses via electro-transport and magnetic properties measurements. The S50 (sample with deposition thickness around 50 nm) exhibits the highest superconducting transition temperature ( T c ) of 2.62 K, which is higher than that of the bulk LaSi 2 . The variation of T c with film thickness is within 8 %. In addition, the upper critical field ( H c2 ) increases with reducing film thickness. Especially for the thinnest LaSi 2 film with deposition thickness around 10 nm, the H c2 shows a sharp increase and the flux jump activity disappears, which is due to the defects and disorders from the interfacial effect. Our work completes the superconducting properties of LaSi 2 films, which helps to understand the influence and modulation of film thickness on superconductivity in LaSi 2 system.