The effect of the addition of Ga
2O
3, a conditional glass former, on the glass-forming ability and superconducting properties of samples with Bi
2-xGa
xSr
2Ca
2Cu
3O
y (
x=0-1.5) compositions has been investigated. The quantity
Tx-Tg increases from 54 to 68K, indicating an improvement in the glass forming ability of the samples, where
Tg and
Tx are glass transition and crystallization temperatures, respectively. The superconducting properties deteriorate due to the migration of Ga ions into the 2212 phase: the superconducting critical temperature of the 2212 phase decreases from 85K for Ga-free sample to 72K for the sample with
x=0.5, and the sample with
x=1.5 shows semiconducting properties. The
c-axis length of the 2212 phase decreases from 3.081nm for Ga-free sample to 3.074nm for the sample with
x=0.5, but
a-and
b-axis lengths remain constant. A new Ga-compound formed in Ga-added samples was identified to be GaSr
0.55Ca
1.05Cu
0.5O
x. Superconducting phases of the Ga-based system are not formed even in Ga-rich samples.
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