We investigate the effect of Ni and Zn substitutions for Cu on the lat
tice parameters, phonon vibrational feature, electronic structure, as
well as transport properties in Bi2Sr1.8La0.2CuOy. The experimental da
ta show that both Ni and Zn are soluble in the Bi2Sr1.8La0.2CuOy mater
ial up to about 10% of the Cu content. In Bi2Sr1.8La0.2Cu1-xNixOy syst
em, the superconducting critical temperature T-c decreases linearly wi
th Ni concentration and the rate of T-c decrease is around 2.5 K/at.%,
while for Bi2Sr1.8La0.2Cu1-xZnxOy system the dependence of T-c on the
Zn dopant concentration deviates from a linear behavior and the Zn su
bstitution suppresses the T-c much stronger than the Ni substitution.
The comparison of the phonon vibrational feature of the apical oxygen
atoms in the CuO6 octahedron between the Bi2Sr1.8La0.2Cu1-xNixOy and B
i2Sr1.8La0.2Cu1-xZnxOy systems shows that the Zn substitution leads to
a more serious structure distortion than the Ni substitution. In addi
tion, the electronic structures of the two doped systems were compared
using XPS spectrum. The results show that the Zn substitution reduces
Cu oxidation level more remarkably than the Ni substitution. Some pos
sible explanations for the stronger suppression of T-c by the Zn subst
itution than by the Ni substitution are provided, based on these exper
imental results.