Weak ferromagnetic properties of Eu1.85Ca0.15CuO4

A weak ferromagnetic transition has been observed for the T'-type compound Eu1.85Ca0.15CuO4. The samples were prepared by a high pressure (5 GPa) synt hesis technique. Their transition temperature occurred at 27 K. At 5 K the residual magnetization was 0.033 emu/g, the coercive force was 6.3 x 10(4) A/m and the saturation field was larger than 1.6 x 10(5) A/m. A field cooli ng method is proposed as a very convenient way to determine the residual ma gnetization and coercive force. The compound Eu1.85Ca0.15CuO4 is suggested to use as a sensor to measure the remanant held of SQUID magnetometer.