1. Synthesis and Characterization of Magnetic Properties of Calcium Hexaferrite Nano Structure
Behzad Abasht

2.  Content
Introduction Material and methods Results Conclusions

3.  Magnetic Ferrites
Ferrite can be divided into three categories namely spinel, hexagonal and garnets according to their crystal lattice structure. significant physical and chemical properties such as good chemical stability, higher microwave magnetic loss, high Curie temperature and moderately large magnetization.

4.  Hexagonal Ferrites

5.  Magnetoplumbite Structure

6.  BaO-Fe2O3

7.  CaO-Fe2O3
no M-type calcium ferrite exists in spite of the close chemical affinity of calcium, strontium and barium.

8.  Effect of La2O3
Ichinose and Kurihara have shown that the M structure in the calcium compound can be stabilized in the presence of some ions like La(III).
CaFe4O7 plays the role of precursor in M phase formation.
The effect of La2O3 on CaFe4O7 is to decompose CaFe4O7 into M phase and CaFe2O4 and stabilize the M phase

9.  Effect of La2O3

10. Materials and Methods

11.  Raw materials
The co-precipitation method was applied for the preparation of Ca1-XLaXFe12O19.
Chemical grade ferric nitrate (Fe(NO3)3.9H2O), calcium nitrate (Ca(NO3)2.4H2O), lanthanum nitrate (La(NO3)3.6H2O) and sodium hydroxide (NaOH) were used as raw materials.

12.  Method

13.  Method
Mix
Coprecipitation
Washing
NaOH

14.  Method Mix Coprecipitation Washing Drying Calcination 80 °C - 24 h

15. Results

16.  STA

17.  XRD CaFe12O19 samples XRD patterns for the CaFe12O19 samples
(as-precipitated and calcinated at 700, 1100 and 1200 °C) for 1 h.

18.  XRD Ca0.6La0.4Fe12O19 samples
XRD patterns Ca0.6La0.4Fe12O19 samples (as-precipitated and calcinated at 700, 1100 and 1200 °C) for 1 h.

19.  Formation Mechanism

20.  Formation Mechanism

21.  SEM
SEM images of as-precipitated specimens (a) without and (b) with (X=0.4) La.

22.  SEM
SEM images of the specimens (a) without and (b) with (X=0.4) La and calcinated at 1200 °C for 1 h.

23.  XRD Ca1-XLaXFe12O19 samples (X=0.2, 0.4 and 0.6)
XRD patterns for the Ca1-XLaXFe12O19 samples
(X=0.2, 0.4 and 0.6) calcinated at 1200 °C for 1 h.

24.  VSM Hysteresis curves for the Ca1-XLaXFe12O19 samples
(X=0.0, 0.2, 0.4 and 0.6) calcinated at 1200 °C for 1 h.

25.  Magnetic Parameters

26.  Magnetic Parameters

27. Conclusions

28.  Conclusions
1. Calcium hexaferrites were prepared by chemical co- precipitation method with precursors of ferric nitrate, calcium nitrate and lanthanum nitrate. The results showed that CaM ferrite could be prepared at about 1200 °C in the presence of La The SEM investigations reveal that the particles were regular hexagonal platelets with the size range of 1–2 mm in 1200 °C for 1h.

29.  Conclusions
3. According to the XRD patterns, SEM images and VSM investigations, the results exhibited that X=0.4 was a suitable amount of lanthanum for preparing of hexagonal shape particle. 4. Optimum MMax and Hc in 12CFL4 sample were obtained A m2.Kg-1 and kA.m-1 respectively. 5. Substitution of Ca2+ by La3+ in terms of formation of calcium hexaferrite phase included a specific range, using extra amount of dopant led to the formation of LaFeO3 as secondary phase.