Growth of Stable Bilayer CrO 2 /MgB 2 Films by Pulsed Laser Deposition

• DOI: 10.1007/s10948-014-2884-6
• Publication Date: 2014-11-21T16:54:09Z
• Authors: N. S. Alzayed; S. Soltan; M. Shahabuddin; A. El-Naggar; I. V. Kityk; S. E. Qaid; Jafar M. Parakkandy; M. S. Shah; Niyaz Ahmad Madhar
• Keywords: 0103 physical sciences; 01 natural sciences

We have used the pulsed laser deposition (PLD) technique followed by post-annealing process with magnesium vapor at 700∘C for 30 min to grow a high-quality CrO2/MgB2 bilayer prepared on Al2O3 (1102) single crystal. The X-ray diffraction patterns showed high-quality orientated growth of MgB2 phase. The obtained films were approximately 300 nm thick and had lateral dimensions of 5×5 mm2. SQUID magnetometry, magneto-optical Faraday microscopy, and magneto-transport techniques were used in order to measure the critical current density (JC) that was found to be 7– 9×106 A/cm2 at 15 K. Transition temperature (TC) for the films was ∼37 K. The obtained magnetic hysteresis loops at low temperatures exhibited asymmetry with respect to H = 0. This can be explained in terms of pinning of flux lines in the films due to magnetic interaction with the ferromagnetic CrO2 layer.