De Haas-van Alphen oscillations in the quasi-two-dimensional organic metal (BEDO-TTF)5[CsHg(SCN)4]2

The magnetization oscillations in the quasi-two-dimensional organic metal (BEDO-TTF)₅CsHg(SCN)₄]₂ are thoroughly investigated over a wide range of magnetic field directions at different temperatures down to 0.4 K. The results obtained are in good agreement with the shape and sizes of the Fermi surface calculated from the x-ray diffraction data. Apart from the fundamental frequencies, the combination frequencies are found in the magnetization oscillation spectrum. It is demonstrated that these combination frequencies are governed by the motion of charge carriers along the real closed orbits inside the network of magnetic breakdown orbits formed under the action of the magnetic field. It is uniquely established that the combination frequencies previously revealed in the magnetoresistance oscillation spectrum of the same metal are associated with the quantum interference effect. The angular dependences of the oscillation amplitude exhibit minima, which are explained by the spin splitting of the Landau levels.