Multiple ordered phases in the filled skutterudite compound PrOs$_{4}$As$_{12}$

Magnetization, specific heat, and electrical resistivity measurements were made on single crystals of the filled skutterudite compound PrOs$_{4}$As$_{12}$. Specific heat measurements indicate an electronic specific heat coefficient $gamma$ $sim 50-200$ mJ/mol K$^{2}$ at temperatures 10 K $leq T leq 18$ K, and $sim 1$ J/mol K$^{2}$ for $T leq 1.6$ K. Magnetization, specific heat, and electrical resistivity measurements reveal the presence of two, or possibly three, ordered phases at temperatures below $sim 2.3$ K and in fields below $sim 3$ T. The low temperature phase displays antiferromagnetic characteristics, while the nature of the ordering in the other phase(s) has yet to be determined.