Effect of anion ordering in the superconducting phase of (TMTSF)/sub 2/CIO/sub 4/

Summary form only given. The static magnetization in the superconducting phase of (TMTSF)/sub 2/CIO/sub 4/ is measured over the temperature range from 0.7K to 4.2K at a cooling rate through the CIO/sub 4/ anion ordering temperature (/spl tilde/24K) from 0.3K/min to 37K/min. With increasing cooling rate, the temperature of superconducting transition continuously decreases from 1.2K at a cooling rate of 0.3K/min to 0.9K at one of 12K/min. In the rapid cooling case (37K/min), the superconducting phase is not observed above 0.7K. In the same cooling rate region (/spl tilde/30K/min), the SDW transition is observed by /sup 1/H-NMR measurements around 4K. The results are discussed in connection with theories of randomness which is caused by the imperfectness of anion ordering and competition with the SDW phase.