We describe the formation of fermionic NaLi Feshbach molecules from an ultracold mixture of bosonic ${}^{23}$Na and fermionic ${}^6$Li. Precise magnetic field sweeps across a narrow Feshbach resonance at 745 G result in a molecule conversion fraction of $5\%$ for our experimental densities and temperatures, corresponding to a molecule number of $5\times {10}^4$. The observed molecular decay lifetime is $1.3$ ms after removing free Li and Na atoms from the trap. Due to its extremely low reactivity, NaLi molecules in the ground state will have a much longer lifetime than KRb.

• Received 23 May 2012

DOI:https://doi.org/10.1103/PhysRevA.86.021602