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With homemade acicular α-FeOOH as raw materials, chemical precipitation - local regularity prepared rod BaCo x Y x Fe 12-2x O 19 (Y = Ti or Sn, feeding doping 0 ≤ x ≤ 0.8). And studied the x and Y on BaCo x Y x Fe 12-2x O 19 composition, morphology and magnetic effects. The results showed that with the feeding doping x increases, Co 2 / Y 4 replace Fe 3 increased, BaCo x Y x Fe 12-2x O 19 lattice parameters increases, crystallinity and increase the degree of impurity α-Fe 2 O 3 content increased, the particle aspect ratio increases and the metal ion mass change, thereby promoting BaCo x Y x < / sub> Fe 12-2x O 19 of Hc were decreased with the increase of x, BaCo x Ti x Fe 12-2x O 19 , Ms increasing x showed increasing trend after the first drop, and BaCo x Sn x < / sub> Fe 12-2x O 19 , Ms with x increases. But the rod BaCo x Y x Fe 12-2x O 19 prominent shape anisotropy, so Hc higher than the literature irregular bulk materials Hc. Dopant ions Y 4 types of changes, so BaCo x Y x Fe 12-2x O 19 (Y = Ti, x = 0.5) showed a slightly higher degree of crystallinity and a higher impurity α-Fe 2 O 3 content, slightly lower aspect ratio and ion magnetic particles and ion mass differences, and thus it presents a higher Hc, Ms and Mr values. With homemade acicular γ-FeOOH as raw materials, respectively NiCO 3 , Ni (OH) 2 and Na 2 C 2 O 4 as a precipitating agent, the use of chemical precipitation - both locally structured method to obtain rod NiFe 2 O 4 . By XRD, SEM, EDS, TG / DTA, FTIR and VSM characterization techniques such as precipitation agent preparation of three kinds of NiFe 2 O 4 formation process, which reveals precipitant type on NiFe 2 O 4 morphology, crystallinity and the extent and magnetic properties and why. The results show that the three different precipitants are prepared by a nickel salt precursor γ-FeOOH precipitate formed coated acicular or rod (i.e. precursor) complexes. Precursor in the roasting process after γ-FeOOH off-OH, nickel salt decomposition, intermediate phase γ-Fe 2 O 3 and NiO intermediate phase further reaction endproducts NiFe 2 O 4 . Precursor of the nickel salt and the kind and degree of crystallinity of interaction with γ-FeOOH the differences between their roasting process causes the nickel salt decomposition temperature and thermal effects, crystallinity and the middle level of the NiO phase, γ-FeOOH de-OH Rate and intermediate phase γ-Fe 2 O 3 differences in the occurrence of phase transition, resulting in NiFe 2 O 4 the degree of crystallinity and ascending order and particle aspect ratio NiFe 2 O 4 (NaCO 3 ) gt; NiFe 2 O 4 (NaOH) gt; NiFe 2 O 4 (Na 2 C < sub> 2 O 4 ). Thereby promoting the NiFe 2 O 4 of Hc by NaCO 3 , NaOH, Na 2 C 2 < / sub> O 4 order descending order, while Ms increased by the same sequence. Respectively homemade acicular γ-FeOOH and α-FeOOH as raw materials, chemical precipitation - both locally structured method to obtain rod Co 1-2x Ni x Zn x Fe 2 O 4 (feeding doping x = 0 or 0.1), and studied different FeOOH raw materials and Ni 2 / Zn 2 doping on Co 1-2x Ni x Zn x Fe 2 O 4 composition, crystallinity and degree, morphology and magnetic properties. The results showed that α-FeOOH as raw material obtained Co 1-2x Ni x Zn x Fe 2 O 4 degree of crystallinity and particle aspect ratio, Hc and Ms are higher than in γ-FeOOH as raw material obtained Co 1-2x Ni x Zn x Fe 2 O 4 ; Ni 2 / Zn 2 partially replace Co 2 the Co 1-2x Ni x Zn x Fe 2 O 4 than CoFe 2 O 4 to improve the purity, crystallinity and lower aspect ratio particles and ions occupying lower case changes, thus making Hc than CoFe 2 O 4 reduced, while Ms than CoFe 2 O 4 increase .
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