Spin glass and magnetoelectric effect in BiFeO3-Bi0.5K0.5TiO3-Bi0.5Na0.5TiO3 single crystals.

We report a cluster spin glass behavior, multiferroicity and magnetoelectric (ME) effects in the single crystals of 0.46 BiFeO 3 -0.54 Bi 0.5 (K 0.31 Na 0.69) 0.5 TiO 3. The crystals are found to possess a pseudo-cubic structure with a weak tetragonal distortion and show ferroelectricity at room temperature with a ferroelectric curie temperature of T C ∼ 630.1 K. The cluster spin glass state in the crystal is evidenced by detailed dc and ac magnetic experiments, including thermo-remnant magnetization, aging effect, memory effect, etc. Magnetodielectric effects, poling enhanced magnetism, and electric field induced acceleration of magnetization relaxation in the spin glass state are observed and ascribed mainly to spin-lattice coupling. These results might suggest an effective route to improve ferromagnetism and ME effects by constructing a spin glass state in BiFeO 3 -based antiferromagnetic multiferroics. [ABSTRACT FROM AUTHOR]