Experimental investigation of ultrasonic velocity anisotropy in magnetic fluids: Influence of grain–grain interaction

Pramana

Kruti Shah¹  R V Upadhyay1¹ 

[1] D. Patel Institute of Applied Sciences and K.C. Patel R & D Center, Charotar University of Science & Technology, Education Campus, Changa 388 421, India$$

关键词: Magnetic fluids;    ultrasonic wave;    sound velocity;    anisotropy.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

Magnetic field-induced dispersion of ultrasonic velocity in a Mn0.7Zn0.3Fe2O4 fluid (applied magnetic field is perpendicular to the ultrasonic propagation vector) is determined by employing continuous wave method. The magnitude of dispersion initially decreases with increasing field, then increases and reaches a plateau at higher fields. Results indicate that the velocity anisotropy is dominated by grain–grain interactions rather than grain–field interaction. At the critical temperature, the grain–grain interaction becomes weak as the transverse component of the particle/cluster moment is larger than the longitudinal one and the system reaches saturation even at low field. These observed variations in the field-induced anisotropy are analysed by incorporating the moment distribution of particles in Tarapov’s theory (J. Magn. Magn. Mater. 39, 51 (1983)).

【 授权许可】

Unknown