Journal of the American Ceramic Society, Vol.97, No.11, 3609-3614, 2014
Comparative Study of the Layered Perovskites Pr(1-x)A(1+x)CoO(4), (A = Sr, Ca)
We present structural, magnetic, and electric properties of Pr1-xCa1+xCoO4 layered perovskites and compare them with the results of recently studied Pr1-xSr1+xCoO4. The Rietveld refinements of X-ray powder diffraction (XRD) patterns indicate that all samples crystallize in the K2NiF4-type structure with space group symmetry I4/mmm. The parent compounds Pr(Ca, Sr)CoO4 are paramagnetic insulators. Upon increasing x, a variety of different magnetic transitions can be identified. The complex magnetic behavior results from the interplay of competing interactions. The temperature-dependent electrical resistivity of the samples shows 2D variable range hopping (2D-VRH). The results are discussed with respect to structure-property relationships.