Mixing-Demixing transition in 1D boson-fermion mixture at low fermion   densities
  We numerically investigated the mixing-demixing transition of the boson-fermion mixture on a 1D lattice at an incommensurate filling with the fermion density being kept below the boson density. The phase diagram we obtained suggested that the decrease of the number of the fermions drove the system into the demixing phase. 
Yousuke Takeuchi and Hiroyuki Mori