Crystallographic, magnetic and electrical properties of Ni0.5Cu0.25Zn0.25LaxFe2−xO4 nanoparticles fabricated by sol–gel method

Impact of La3+ and Y3+ ion substitutions on structural, magnetic and microwave properties of Ni0.3Cu0.3Zn0.4Fe2O4 nanospinel ferrites synthesized via sonochemical route

“…The pure NiCuZn ferrite displays the highest M s magnitudes of 55.5 and 88.3 emu g À1 at 300 K and 10 K, respectively. These magnitudes agreed very-well with those reported in NiCuZn nanoferrites prepared via sol-gel auto-combustion process 39,40 and in NiCuZn thin lms. 41 We have observed that there is no improvement in the M s magnitudes with substitutions.…”

Influence of La3+ Substitution on Structure, Morphology and Magnetic Properties of Nanocrystalline Ni-Zn Ferrite

“…However, it is difficult for lanthanum ion to substitute Fe 3+ as La 3+ has much larger ionic radius than that of Fe 3+ and requires more activation energy to enter octahedral sites as the bond energy of La-O is higher as compared to Fe-O. Therefore, instead of occupying the Fe 3+ sites in the lattice the La 3+ enter the lattice at interstitial sites due to extra stress coming from partial lanthanum ion which suppresses the crystallization of Ni-Zn ferrites [50, 51]. …”

“…FTIR spectra demonstrate the presence of two fundamental absorption bands which are attributed to the normal and inverse cubic spinel ferrites. Generally the higher frequency absorption band ‘ν 1 ’ appears in the range of 500 to 600 cm -1 represents the intrinsic vibration of tetrahedral group, while the octahedral groups are represented by the lower frequency absorption band ‘ν 2 ’ in the range of 350–490 cm -1 [54, 55]. Since the tetrahedral site dimensions are less as compared to the octahedral, the band frequency of ‘ν 1 ’ is higher than the ‘ν 2 ’ absorption band [56].…”

“…This is also due to the substitution of nonmagnetic lanthanum ion which leads to the formation of the nonmagnetic spinel structure. In addition to this, the substitution of La 3+ ion causes the transformation of the collinear ferromagnetic order into non-collinear arrangement and disintegration of ferromagnetic order that reduces the M s [50]. …”

Structural Properties and Cation Distribution in Co2+ and Ho3+ Ions Induced Nanocrystalline ZnFe2O4

“…The average particles size was obtained by Scherrer's formula and is listed in Table 1, which is found to be in the range of 25-30 nm. X-ray densities (dx) of all the investigated samples were calculated from X-ray diffraction analysis and by using the relation [21]:…”