364
M. Satalkar et al.
Table 23.3 Ni content dependence of oxygen positional parameter (u 43m ), shared tetrahedral edge
length (d AE ), shared (d BE ) and unshared octahedral edge length (d BEu ), and tetrahedral (R A ) and
octahedral bond length (R B ) for ann. (500 ◦ C/3 h) Zn 0.75−x Ni x Mg 0.15 Cu 0.1 Fe 2 O 4 system
x
u 43m
d AE (nm)
d BE (nm)
d BEu (nm)
R A (nm)
R B (nm)
0.00
0.3796
0.3073
0.2853
0.2964
0.1882
0.2056
0.15
0.3799
0.3086
0.2851
0.2970
0.1890
0.2058
0.30
0.3800
0.3084
0.2845
0.2966
0.1889
0.2054
0.45
0.3807
0.3086
0.2818
0.2953
0.1890
0.2040
0.60
0.3806
0.3078
0.2811
0.2946
0.1885
0.2035
0.75
0.3797
0.3058
0.2835
0.2949
0.1873
0.2045
up to x = 0.45 and reduces for 0.45 < x ≤ 0.75. For ideal cubic closed packed spinel
structure, u ideal
43m = 0.375 [43]. The calculated u parameter values are greater
than the ideal value (u ideal
43m = 0.375) for entire Zn 0.75−x Ni x Mg 0.15 Cu 0.1 Fe 2 O 4
nano-ferrite revealing distortion in the spinel structure. u 43m and a exp. values were
also utilized in the calculation of other cation distribution parameters, demonstrated
in Table 23.3: d AE , d BE , d BEu , R A , and R B using the relations [51]. The observed
variation in tetrahedral bond length (R A ) and shared tetrahedral edge (d AE ) is in
accordance with the changes in the ionic radii of A site (r A ) with Ni content (x).
Decrease in octahedral bond length (R B ) and shared and unshared octahedral edge
(d BE , d BEu ) with Ni doping is accredited to the replacement of larger ion (Zn 2+ ) by
smaller ion (Ni 2+ ).
23.3.3 SEM, EDAX
Representative low-magnification (LM) and high-magnification (HM) SEM images
for the composition x = 0.00 and x = 0.45 shown in Fig. 23.2 depict difference
in surface morphology, porosity, and particle agglomeration with diverse shapes
and sizes. This difference signifies that presence or absence of Ni ion in Zn-MgCu ferrite plays an imperative role in microstructure of prepared spinel ferrite.
The encircled area of SEM images represents the magnified region of the image.
The non-connected spherical pores are noticeably visible in the LM and HM SEM
images of x = 0.00 with dissimilar pore sizes (555.70, 768.37, and 1.30 μm), which
are missing for x = 0.45. The HM SEM image of the sample with x = 0.45 shows
large particle clusters with a planar and homogeneous surface. Pores present in
sample, x = 0.00, are accredited to the liberation of large quantity of gases during
combustion process [52], which would also get influenced by different amounts
of nitrate/acetate salts of Zn, Ni, Mg, Cu, and Fe ions and citric acid used for
synthesizing the studied samples [53], leading to changes in the pore sizes. Pores
affect saturation magnetization (M s ), grain size (D), and surface area (S) of the
M. Satalkar et al.
Table 23.3 Ni content dependence of oxygen positional parameter (u 43m ), shared tetrahedral edge
length (d AE ), shared (d BE ) and unshared octahedral edge length (d BEu ), and tetrahedral (R A ) and
octahedral bond length (R B ) for ann. (500 ◦ C/3 h) Zn 0.75−x Ni x Mg 0.15 Cu 0.1 Fe 2 O 4 system
x
u 43m
d AE (nm)
d BE (nm)
d BEu (nm)
R A (nm)
R B (nm)
0.00
0.3796
0.3073
0.2853
0.2964
0.1882
0.2056
0.15
0.3799
0.3086
0.2851
0.2970
0.1890
0.2058
0.30
0.3800
0.3084
0.2845
0.2966
0.1889
0.2054
0.45
0.3807
0.3086
0.2818
0.2953
0.1890
0.2040
0.60
0.3806
0.3078
0.2811
0.2946
0.1885
0.2035
0.75
0.3797
0.3058
0.2835
0.2949
0.1873
0.2045
up to x = 0.45 and reduces for 0.45 < x ≤ 0.75. For ideal cubic closed packed spinel
structure, u ideal
43m = 0.375 [43]. The calculated u parameter values are greater
than the ideal value (u ideal
43m = 0.375) for entire Zn 0.75−x Ni x Mg 0.15 Cu 0.1 Fe 2 O 4
nano-ferrite revealing distortion in the spinel structure. u 43m and a exp. values were
also utilized in the calculation of other cation distribution parameters, demonstrated
in Table 23.3: d AE , d BE , d BEu , R A , and R B using the relations [51]. The observed
variation in tetrahedral bond length (R A ) and shared tetrahedral edge (d AE ) is in
accordance with the changes in the ionic radii of A site (r A ) with Ni content (x).
Decrease in octahedral bond length (R B ) and shared and unshared octahedral edge
(d BE , d BEu ) with Ni doping is accredited to the replacement of larger ion (Zn 2+ ) by
smaller ion (Ni 2+ ).
23.3.3 SEM, EDAX
Representative low-magnification (LM) and high-magnification (HM) SEM images
for the composition x = 0.00 and x = 0.45 shown in Fig. 23.2 depict difference
in surface morphology, porosity, and particle agglomeration with diverse shapes
and sizes. This difference signifies that presence or absence of Ni ion in Zn-MgCu ferrite plays an imperative role in microstructure of prepared spinel ferrite.
The encircled area of SEM images represents the magnified region of the image.
The non-connected spherical pores are noticeably visible in the LM and HM SEM
images of x = 0.00 with dissimilar pore sizes (555.70, 768.37, and 1.30 μm), which
are missing for x = 0.45. The HM SEM image of the sample with x = 0.45 shows
large particle clusters with a planar and homogeneous surface. Pores present in
sample, x = 0.00, are accredited to the liberation of large quantity of gases during
combustion process [52], which would also get influenced by different amounts
of nitrate/acetate salts of Zn, Ni, Mg, Cu, and Fe ions and citric acid used for
synthesizing the studied samples [53], leading to changes in the pore sizes. Pores
affect saturation magnetization (M s ), grain size (D), and surface area (S) of the