Author: Daniel Joseph Scanderbeg

Publisher:

Published: 2007

Total Pages: 101

ISBN-13:

Sm2̳-̳x̳Ce̳x̳CuO4̳-̳y̳ belongs to a class of materials known as electron-doped superconductors (Ln2̳-̳x̳Mx̳CuO4̳-̳y̳;Ln = Pr, Nd, Sm, Eu; M = Ce, Th) and has a moderately high superconducting critical temperature, Tc̳, of ~ 20 K at optimal doping (x = 0.15). The trivalent rare earth site is doped with tetravalent Ce or Th; hence the name "electron-doped". Sm2̳-̳x̳Ce̳x̳CuO4̳-̳y̳ also exhibits a unique magnetic structure at low temperatures (T 6 K) due to the antiferromagnetic ordering of the Sm3 ions. In this study, thin films of the electron-doped superconductor Sm2̳-̳x̳Ce̳x̳CuO4̳-̳y̳ (SCCO) have been grown by pulsed laser deposition (PLD) for a cerium concentration range of x = 0.13 to x = 0.19. The films have been characterized through x-ray diffraction, electrical transport, and thermal transport measurements. A temperature versus cerium content (T-x) phase diagram has been constructed from the electrical transport measurements and yields a superconducting region similar to that of two of the other electron-doped superconductors Nd2̳-̳x̳Ce̳x̳CuO4̳-̳y̳ and Pr2̳-̳x̳Ce̳x̳CuO4̳-̳y̳. Thermopower measurements were also performed on the samples and show a dramatic change from the underdoped region (x