De Haas-van Alphen Effect and Fermi Surface Properties in Nearly Ferromagnet SrCo2P2

We grew high-quality single crystals of SrCo2P2 with the ThCr2Si2-type tetragonal structure, and clarified the Fermi surface properties by carrying out de Haas-van Alphen (dHvA) experiments and energy band calculations. SrCo2P2 is known to be a nearly ferromagnetic compound, where the magnetic susceptibility follows the Curie-Weiss law above 200 K, with the effective magnetic moment mu(eff) = 1.72 mu(B)/Co, but becomes almost constant below about 100 K. The electronic specific heat coefficient gamma is thus relatively large, being gamma = 40 mJ/(K-2.mol). Detected dHvA branches possess the corresponding cyclotron effective masses m(c)*, ranging from 0.87 to 7.2 m(0) (m(0): rest mass of an electron). The angular dependences of the dHvA frequencies are well explained by the results of full-potential linearized augmented plane wave (FLAPW) energy band calculations, revealing a multiply-connected band 25th hole Fermi surface and a compensated nearly cylindrical band 26th electron Fermi surface. It is thus concluded that the electronic state of SrCo2P2 is nearly three-dimensional rather than two-dimensional.