Jp. Sydow et al., GROWTH AND PROPERTIES OF YSR2CU2.75MO0.25O7-DELTA THIN-FILMS, IEEE transactions on applied superconductivity, 7(2), 1997, pp. 2138-2141
We report on the epitaxial growth of YSr2Cu2.75Mo0.25O7-delta (YSCMO)
thin films by pulsed laser ablation, and discuss the superconducting a
nd normal state transport properties of microbridges patterned from su
ch films. To investigate the dopant oxygen mobility of this material,
we have used electrical biases applied at near room temperature to ind
uce long range displacement of chain oxygen vacancies in these microbr
idges, We find that with electromigration, the T-c of the microbridges
can be raised to greater than or equal to 60 K. This transition tempe
rature is higher than any previously achieved for this compound, inclu
ding the T-c's achieved as result of extended very high pressure oxyge
n anneals, or by high pressure in situ measurements. Micro-Raman spect
roscopy measurements have been used to examine and characterize the ox
ygen order in the film before and after electromigration. These measur
ements indicate that, as suggested by the final T, achieved, a very hi
gh degree of oxygenation and chain oxygen order can be induced in the
microbridge by this process. Thus the as-grown properties of YSCMO app
ear to be dominated by the low level of oxygenation and the low degree
of oxygen homogeneity obtained by normal annealing processes.