Ba-Ferrite single crystals were prepared and the magnetic and thermal properties were characterized by Mossbauer spectroscopy. The single crystal layer was cut in the c-axis and radiated to the surface by ${gamma}$-rays for Mossbauer spectroscopy. We found out that the spin states in Fe ions were parallel to the ${gamma}$-rays direction and the whole crystal bulk formed only one crystal with the same spin direction. $M"{o}ssbauer$ spectra in single crystal have only 4 sets of 4 absorption lines in each Fe site when the ${gamma}$-rays have the same radiation direction with the c-axis in the crystal, and there was no 2b-site spectrum. The zero absorption of 2b-site means that there was a fast diffusion motion in a double-well atomic potential at room temperature, in which bipyramidal Fe ions have the two minima at each side mirror plane.