  Magnetic susceptibility, specific heat, and neutron powder diffraction
measurements have been performed on polycrystalline Li2Co(WO4)2 samples. Under
zero magnetic field, two successive magnetic transitions at TN1 ~ 9.4 K and TN2
~ 7.4 K are observed. The magnetic ordering temperatures gradually decrease as
the magnetic field increases. Neutron diffraction reveals that Li2Co(WO4)2
enters an incommensurate magnetic state with a temperature dependent k between
TN1 and TN2. The magnetic propagation vector locks-in to a commensurate value k
= (1/2, 1/4, 1/4) below TN2. The antiferromagnetic structure is refined at 1.7
K with Co2+ magnetic moment 2.8(1) uB, consistent with our first-principles
calculations.
