Recently, we have been successful in the single crystal growth of CeAg₂Ge₂ by flux method using the Ag-Ge binary alloy as flux.

CeAg₂Ge₂ crystallize in the well known ThCr₂Si₂ type crystal structure. Although this compound is existing in literature for more than 20 years, no single crystal data is available, owing to the difficulty in growing the single crystal from a stoichiometric melt. We have successfully grown the single crystals of CeAg₂Ge₂ from an off-stoichiometric melt, with excess of Ag and Ge. A clear anisotropy and an antiferromagnetic transition at T_N = 4.6 K have been observed in the magnetic property measruements. One of the interesting results is that the entropy reaches R ln 4 at 20 K indicating that the ground state and the first excited state are very closely spaced (a quasi-quartet state). From the sepcific heat measurements and crystalline electric field (CEF) analysis of the magnetic susceptibility, we have found the level splitting energies as 5 K and 130 K.  The magnetization measurements reveal that the a-axis as the easy axis of magnetization and the saturation moment is 1.6 muB/Ce, corroborating the previous neutron diffraction measurements on a polycrystalline sample.

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