AbstractWe report the effect of chemical pressure on the ferromagnetic ordering of the recently reported n-type diluted magnetic semiconductor Ba(Zn$$_{1-x}$$
1
-
x
Co$$_{x}$$
x
)$$_{2}$$
2
As$$_{2}$$
2
which has a maximum $$T_C$$
T
C
$$\sim$$
∼
45 K. Doping Sb into As-site and Sr into Ba-site induces negative and positive chemical pressure, respectively. While conserving the tetragonal crystal structure and n-type carriers, the unit cell volume shrink by $$\sim$$
∼
0.3$$\%$$
%
with 15$$\%$$
%
Sr doping, but drastically increase the ferromagnetic transition temperature by 18$$\%$$
%
to 53 K. Our experiment unequivocally demonstrate that the parameters of Zn(Co)As$$_{4}$$
4
tetrahedra play a vital role in the formation of ferromagnetic ordering in the Ba(Zn,Co)$$_{2}$$
2
As$$_{2}$$
2
DMS.