Shubnikov-de Haas oscillations in NbSe3

We have measured the resistivity of the linear transition metal trichalco-genide NbSe₃ in magnetic fields up to 180 kG. We observe large Shubnikov-de Haas oscillations. The measurements reveal a strong anisotropy in the a.c. plane perpendicular to the chain direction. A ratio of 3 in the cyclotron effective masses for the two orthogonal directions in this plane is determined. Spin splitting occurs for high magnetic field, and we obtain a Landé factor g of 2.45.