Magnetic Ordering in Yb$_{4}$LiGe$_{4}$

R$_{5}$T$_{4}$ compounds (R = rare earth, T = Ge or Si) are interesting because the magnetic properties depend sensitively on changes in the crystalline structure. Yb$_{5}$Ge$_{4}$ such a compound, with (presumed) AFM order occurring at T$_{N}$ = 1.7 K. We are interested in the effects of substituting Li in place of one Yb atom. Previous measurements of the magnetic properties of polycrystalline Yb$_{4}$LiGe$_{4}$ using NMR, specific heat, and resistance measurements at temperatures down to 0.5 K and in magnetic fields up to 4 T were made for comparison with the parent compound. The resistance measurements showed a maximum at 1.1 K, which may indicate the onset of magnetic order. Thus we performed $\mu $SR measurements on Yb$_{4}$LiGe$_{4}$ and Yb$_{5}$Ge$_{4}$, and analysis of the data confirmed magnetic ordering (possibly AFM) at 1.1 K. $\mu $SR also revealed a dependence on the magnetic history of the sample. Currently we are studying the pressure dependence of the (presumed) T$_{N}$ to explore if increased pressure can drive the T$_{N}$ to 0 K, and results will be discussed.