Preparation of BiSrCaCuO Multilayers by Use of Slower Q-switched 266 nm YAG Laser

Abstract

Multilayers of Bi2Sr2Ca1Cu2O x /Bi2Sr2Cu1O x were prepared by pulsed laser deposition (PLD) using the fourth harmonic 266 nm YAG. Compared to an excimer laser, YAG PLD required the higher oxygen atmosphere. The higher oxygen pressure together with the lower energy generated by YAG laser collapsed the region of plume emission. In order to produce the same energy density as an excimer, only Q-switch was modulated by 2 Hz while the flash lamp kept the original repetition rate of 10 Hz. With the rate of 2 Hz, we obtained the higher energy density per pulse, and more stable laser output of the fourth harmonics, 266 nm. To characterize the multilayers, reflection high-energy electron diffraction (RHEED) and X-ray diffraction (XRD) were employed, and indicative of epitaxial layers with limited in-plane order. The resistivities of multilayers were measured by the Van der Pauw method, and showed the temperatures of superconducting transition, T c0 (R=0), around 65 K on the multilayers.

Potential of Nd:YAG pulsed laser deposition method for coated conductor production

“…For example, critical temperatures (T c ) of Bi 2 Sr 2 CaCu 2 O y (Bi-2212) superconducting films reached 83 K on Y 2 O 3 stabilized zirconia and MgO substrates [1] and 95 K on Si substrates with SiO 2 or SrTiO 3 buffers [2] by using k = 1064 nm. For electric device application, fabrications of multilayer films such as Pb-Zr-Ti-O/Y123 [3], Y123/ SrTiO 3 [4], Y123/Bi-2212 [5] and Bi-2212/Bi-2223 [6] were also investigated. Here, these multilayer films were deposited by using k = 266 nm except for the Pb-Zr-Ti-O/Y123 multilayer film which was prepared by using k = 355 nm.…”

- Polar Coincident Site Lattice Figure -

“…Bi-2212 thin films were prepared by pulsed laser deposition using "slower Q-switched Nd:YAG laser" [20] at the repetition rate of 2 Hz generated by 10 Hz modulated flash lamp with secondary function generation. Targets were prepared by stoichiometric ratio of Bi 2 O 3 , SrCO 3 , CaCO 3 and CuO powders, which were ground and calcined for total four hours in oxygen atmosphere at 800°C.…”

Structural modulation in bismuth cuprate superconducting film with continuous epitaxial growth

“…A slower Q-switched YAG [14,15] was used to prepare epitaxial Bi-2212(0 0 1) films on MgO(0 0 1) substrates by means of pulsed laser deposition (PLD). High-resolution X-ray diffractometer (PANalytival X'Pert PRO MRD) verified epitaxial growth of Bi-2212 film by y-2y scan together with f scan, and revealed asymmetric SC peaks around Bi-2212 main peaks around BiÀ2212ð0 0 2 0Þ [15] and ð0 0 1 2Þ [16].…”