The crystal structure of Sr2Y0.8Ca0.2Co2O6 is orthorhombic below 270 K (Immm, a = 3.84029(7) Å, b = 3.80691(6) Å and c = 19.4980(3) Å at 20 K), transformed from tetragonal (I4/mmm, a = 3.82765(6) Å and c = 19.5795(3) Å) at 295 K. The crystal structure distortion is accompanied by an anomalous temperature dependence of the degree of buckling of the CoO2plane and is correlated with the development of anisotropic antiferromagnetic ordering of magnetic moments (2.93(2) μBper Co at 20 K). A magnetically glassy state below about 35 K and variable range hopping conduction below about 64 K for Sr2Y1-xCaxCo3.4+2O 7-z (0.2 ≤ x ≤ 0.5, 0.21 ≤ z ≤ 0.38) were found by magnetic susceptibility and electrical resistivity measurements.
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Materials Science(all)
- Condensed Matter Physics