Novel method for low temperature sintering of barium hexaferrite with magnetic easy-axis alignment

Most applications of hexaferrites require sintered products, but sintering of hexaferrites at high temperatures degrades their magnetic properties and cannot be used as low-temperature co-fired ceramics. Additionally, due to the magnetic uniaxial anisotropy of hexaferrites, excellent magnetic properties are attained when the particles are aligned along the magnetic easy-axis. In order to overcome these problems, herein we suggest a new method to decrease the sintering temperature and improve the simultaneous alignment of magnetic particles along the easy-axis. NaCl-barium hexaferrite particles and NaCl-amorphous particles were sintered using the spark plasma sintering process. Using this method, a sintered body with a relative density of 92.5% and 70.2% alignment was fabricated at 800 °C for 5 min. In this method, the added NaCl played a significant role in facilitating the low temperature sintering and particle alignment. This method was found to be effective for low temperature sintering and nano-scale particle alignment.