  Nd-based pyrochlore oxides of the form Nd$_{2}B_{2}$O$_{7}$ have garnered a
significant amount of interest owing to the moment fragmentation physics
observed in Nd$_{2}$Zr$_{2}$O$_{7}$ and speculated in Nd$_{2}$Hf$_{2}$O$_{7}$.
Notably this phenomenon is not ubiquitous in this family, as it is absent in
Nd$_{2}$Sn$_{2}$O$_{7}$, which features a smaller ionic radius on the $B$-site.
Here, we explore the necessary conditions for moment fragmentation in the Nd
pyrochlore family through a detailed study of the mixed $B$-site pyrochlore
Nd$_{2}$GaSbO$_{7}$. The $B$-site of this system is characterized by
significant disorder and an extremely small average ionic radius. Similarly to
Nd$_{2}$Sn$_{2}$O$_{7}$, we find no evidence for moment fragmentation through
our bulk characterization and neutron scattering experiments, indicating that
chemical pressure (and not necessarily the $B$-site disorder) plays a key role
in the presence or absence of this phenomenon in this material family.
Surprisingly, the presence of significant $B$-site disorder in
Nd$_{2}$GaSbO$_{7}$ does not generate a spin glass ground state and instead the
same all-in-all-out magnetic order identified in other Nd pyrochlores is found
here.
