Crystal structure and physical properties of Cr oxide with K$_{2}$NiF$_{4}$-type structure

Ruddlesden-Popper (RP) type structure materials have been attracted much attention due to their interesting physical properties including high-$T_{\mathrm{c}}$ superconductivity, charge stripe, itinerant ferromagnetism and so on. In this work we are presenting physical properties of some of the K$_{2}$NiF$_{4}$ type structure compounds. YSrCrO$_{4}$ is first synthesized and found to be a hetto-type K$_{2}$NiF$_{4}$ structure. The space group of YSrCrO$_{4}$ is determined to be orthorhombic Pccn by the electron diffraction and the powder X-ray diffraction. YSrCrO$_{4}$ shows two-dimensional (2D) spin correlations and a canted antiferromagnetic (AF) ordering. Evidence of AF ordering of the Cr oxides is obtained microscopically from ESR. The dielectric measurements suggest existence of in-gap states, while no magneto-dielectric coupling was observed in the above compounds.