Hysteretic critical intergrain transport current in superconducting YBa2Cu3O7 as a basis for new switching and data storage effects

In sintered polycrystalline high-T_c superconductors, intergrain I_c depends on the magnetic history of the sample because the intragrain screening currents contribute a hysteretic component to the total B field at the grain interfaces. Experimental results on hysteretic intergrain I_c are presented, and application-relevant aspects of this behavior are investigated. Programmable switching and data storage effects were experimentally verified on the basis of this hysteretic I_c using the remanent state of intragrain magnetization. In the remanent state, information can be stored in the grains and read out by the transport current. Different I_c-values were found at the same B_a and the same intragrain M but different shapes of the intragrain flux density profiles. The time relaxation behavior of intergrain I_c was studied, and a large reduction of relaxation rate was found under certain field cycling conditions. This could be important for future electronic applications