We investigated the anisotropic magnetic properties of CePd2As2 by
magnetic, thermal and electrical transport studies. X-ray diffraction confirmed
the tetragonal ThCr2Si2-type structure and the high-quality of the single
crystals. Magnetisation and magnetic susceptibility data taken along the
different crystallographic directions evidence a huge crystalline electric
field (CEF) induced Ising-type magneto-crystalline anisotropy with a large
c-axis moment and a small in-plane moment at low temperature. A detailed CEF
analysis based on the magnetic susceptibility data indicates an almost pure
⟨±5/2∣ CEF ground-state doublet with the dominantly
⟨±3/2∣ and the ⟨±1/2∣ doublets at 290 K and 330
K, respectively. At low temperature, we observe a uniaxial antiferromagnetic
(AFM) transition at TN=14.7 K with the crystallographic c-direction being
the magnetic easy-axis. The magnetic entropy gain up to TN reaches almost
Rln2 indicating localised 4f-electron magnetism without significant
Kondo-type interactions. Below TN, the application of a magnetic field along
the c-axis induces a metamagnetic transition from the AFM to a
field-polarised phase at μ0Hc0=0.95 T, exhibiting a text-book example
of a spin-flip transition as anticipated for an Ising-type AFM.Comment: 9 Pages, 8 figure