SrCoxZrxFe12−2xO19 and SrNixZrxFe12−2xO19 hexaferrites: A Comparison Study of AC Susceptibility, FC-ZFC and hyperfine interactions
Introduction
Nanosized ferrites (NSF) are magnetic nanoparticles (MNPs) which have found considerable interest and novel uses in recent years. These applications vary from technological uses such as magnetic recording and electromagnetic radiation (EMR) shielding, biomedical uses such as drug delivery and contrast agents, environmental uses including catalysts and adsorbants to use in polymers, batteries, fuel cells, sensors, etc. [1], [2], [3], [4], [5], [6], [7], [8]. Strontium hexaferrites have been discovered in late 1950s in Philips Laboratories in Eindhoven, Netherlands [9] and have been used in many technological applications as hard magnets since then. Strontium hexaferrite (SrM) has a magnetoplumbite structure with a high coercive field (Hc), high anisotropy, and its space group is P63 /mmc. The crystallographic sites of hexaferrites include five sites 12k, 4f1, 4f2, 2a, 2b containing 24 iron ions in two-unit cells in the structure of SrM. Three of those are located on the octahedral (Oh) sites with symmetries 4f2, 2a, 12k whereas the tetrahedral (Td) site, 4f2, is occupied by one iron ion and the 2b symmetry site in the trigonal bipyramidal site is occupied by the other iron ion [10]. Therefore, the structural, electric, and magnetic characteristics of SrM can be tuned by the introduction of different cations into the structure. Different groups have studied the substitution of the cations by various metallic ions. For instance, Abdellahi et al. have introduced both Zn and Zr ions simultaneously to SrM by a mechanical milling method and sintering to decrease its high anisotropy for hyperthermia applications [4]. Iqbal and co-workers synthesized Sr(ZrxCux)Fe12-2xO19 (x = 0.0–0.8) nanoparticles to obtain a lower sintering temperature with optimum size for a use in magnetic recording. The saturation magnetization (Ms) increased, the coercivity (Hr) decreased (137 to 49 KAm−1), and the remanence (Mr) stayed constant up to x=0.04 [11]. R.K. Mudsainiyana et al. [12] prepared Co–Zr doped BaCoxZrxFe(12−2x)O19 (x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) under tow different conditions sol–gel and citrate precursor sol–gel. They found that the coercivity for samples synthesized by sol–gel was decreased in compassion with those prepared via citrate precursor sol–gel. The saturation magnetization and Mössbauer analysis were varied in both conditions. Prabhjyot Kaur at et al. [13] investigated the effect of Co2+ and Zr4+ substitution on magnetic, microwave and electromagnetic characteristics of Sr hexaferrites synthesized by citrate precursor sol-gel method. They noticed that the Co2+ and Zr4+ enhanced the coercivity and preserved high saturation magnetization. Moreover, the microwave absorption features are adjusted with the thickness and the amount of Co2+ and Zr4+.
On the other hand, the emerging trend on strontium hexaferrites is the synthesis and characterization of novel materials where strontium or iron is or both of those are substituted with different ions, especially rare earth metal ions, for the search of unique magnetic properties. For example, samarium doped SrM, Sr1– SmxFe12– xZnxO19 (x = 0.0 - 0.4) were produced by ball-milling followed by a solid-state synthesis at 1473 K by Wu et. al. [14]. The authors found out that the sample where x=0.2 displayed the single phase and the highest saturation magnetization at both 5 K and 300 K, Curie temperature (Tc) decreased with the elevation in the composition. and the coercive force increased along with the temperature and decreased with increasing “x” ratio up to x=0.3 [14]. To understand the exact positions of those dopant ions and hence their effect on the magnetic properties, Mossbauer spectroscopy stays as the correct technique. The high energy (10-12 eV) of Mossbauer spectroscopy enables researchers to obtain detailed information regarding site occupancy and hyperfine interactions in ferrites [5]. Bercoff and co-workers investigated the Co-Nd co-doped SrM nanoparticles (Sr1-xNdxFe12(1-x)CoxO19 (x = 0.0 – 0.4)) by sol-gel auto-combustion followed by calcination [15]. The decrease in the particle size while a very slight change in the cell parameters confirmed the introduction of those dopant ions into the structure easily. Ms values slightly increased from 72 to 76 emu/g as well as the coercivity (26.40 to 58.70 A/m for x = 0.0 - 0.3). Mossbauer analysis showed that the vacancies of irons were not evenly distributed over the lattice. On the other hand, the site for Co/Fe substitution was mainly in the 4f2 site. The migration of ions was promoted by iron and oxygen vacancies so that the substitution of Nd was successful and did not have a significant magnetic difference up to x=0.3 whereas the co-substitution with Nd and Co enhanced their magnetic behavior in the iron-deficient SrM. Many studies in the literature focus just on the room-temperature magnetization behavior of SrM however, to truly understand the thermal effect on the magnetic characteristics of SrM, measurements over a wide range of temperature should be conducted [16].
A comparison study of Sr(CoxZrx)Fe12−2xO19 and Sr(NixZrx)Fe12−2xO19 HFs (x ≤ 0.10) have been presented in previous publication to investigate the structural and magnetic characteristics. It has been found that both compositions showed hard ferrimagnetic (FM) nature at 300 and 10K. Moreover, the Ms, Mr and nB were enhanced for Sr(CoxZrx)Fe12−2xO19 whereas these values are reduced for Sr(NixZrx)Fe12−2xO19 at measured temperatures [17]. As a continuation to our previous paper, we report a comparison study of magnetic properties versus low temperature, ZFC-FC, and AC susceptibility along with Mossbauer spectroscopy for Sr(CoxZrx)Fe12−2xO19 and Sr(NixZrx)Fe12−2xO19 HFs.
Section snippets
Materials and Methods
Sr(CoxZrx)Fe12−2xO19 and Sr(NixZrx)Fe12−2xO19 HFs (x ≤ 0.10) were fabricated with a sonochemical assisted route. Predetermined appropriate amounts of strontium nitrate (99%), zirconium oxynitrate (99%), iron (III) nitrate nonahydrate (98%), cobalt nitrate hexahydrate (99%), and nickel(II) nitrate hexahydrate (99%), were used as initial materials . The detailed synthesis of the products has been already provided in our previous publication [17].
Structure and morphology investigations
The X-ray diffraction powder pattern, SEM and TEM approved the structure and morphology of Sr(CoxZrx)Fe12−2xO19 and Sr(NixZrx)Fe12−2xO19 HFs. The complete structural, spectral and morphological investigations have been already presented in our previous publication [17].
Hyperfine interactions
The correlation between magnetic properties and the structure of hexaferrite nanoparticles, and detailed information on the preference of crystallographic sites by cations can be determined by 57Fe Mössbauer spectroscopy. The
Conclusion
Sr(CoxZrx)Fe12−2xO19 and Sr(NixZrx)Fe12−2xO19 hexaferrites (HFs) were prepared via ultrasonic route. Mössbauer analysis revealed that the Co2+ and Zr4+ ions positioned in octahedral and 2b sites, whereas Ni2+ and Zr4+ ions preferred to reside at octahedral 12k and 4f2 sites. The FC and ZFC magnetization measurements were conducted in a temperature interval of 10–325 K. These measurements revealed the characteristic ferrimagnetic behavior in various synthesized Sr(CoxZrx)Fe12-2xO19 and Sr(NixZrx
Declaration of Competing Interest
There are no conflicts of interest to declare.
References (39)
- et al.
Zn and Zr co-doped M-type strontium hexaferrite: Synthesis, characterization and hyperthermia application
Chinese Journal of Physics
(2018) - et al.
Strontium hexaferrite (SrFe12O19) based composites for hyperthermia applications
J. Magn. Magn. Mater.
(2013) Hexagonal ferrites: A review of the synthesis, properties and applications of hexaferrite ceramics
Progress in Materials Science
(2012)- et al.
Correlation between site preference and magnetic properties of Co–Zr doped BaCoxZrxFe(12−2x)O19 prepared under sol–gel and citrate precursor sol–gel conditions
J. Alloys Compd.
(2014) - et al.
Modulation of physico-chemical, magnetic, microwave and electromagnetic properties of nanocrystalline strontium hexaferrite by Co-Zr doping synthesized using citrate precursor sol-gel method
Ceram. Int.
(2017) - et al.
The influence of Nd–Co substitution on the magnetic properties of non-stoichiometric strontium hexaferrite nanoparticles
J. Magn. Magn. Mater.
(2009) - et al.
Magnetic study of M-type Ru-Ti doped strontium hexaferrite nanocrystalline particles
J. Alloys Compd
(2015) - et al.
Mossbauer and X-ray diffraction study of Co2+–Si4+ substituted M-type barium hexaferrite BaFe12-2xCoxSixO19±ɤ
J. Magn. Magn. Mater.
(2013) - et al.
Cations distribution and magnetic properties of Co–Zr doped BaCoxZrxFe(12−2x)O19 prepared via citrate precursor sol–gel route
Cer. Int.
(2014) - et al.
Effect of site preferences on structural and magnetic switching properties of Co–Zr doped strontium hexaferrite SrCoxZrxFe(12−2x)O19
J. Magn. Magn. Mater.
(2015)
Sol–gel synthesis, structural and magnetic properties of nanoscale M-type barium hexaferrites BaCoxZrxFe(12−2x)O19
J. Magn. Magn. Mater.
Synthesis of Co-Zr doped nanocrystalline strontium hesaferrites by sol-gel auto-combustion route using sucrose as fuel and study of their structural, magnetic and electrical properties
Cer. Int.
Morphology and magnetic traits of strontium nanohexaferrites: Effects of manganese/yttrium co-substitution
J. Rare Earths
Rietveld refinement, morphology and super-paramagnetism of nanocrystalline Ni0.70−xCuxZn0.30Fe2O4 spinel ferrite
Ceram. Int.
Structural and magnetic properties of Ce-Y substituted Strontium nanohexaferrites
Ceram. Int.
AC susceptibility and Mossbauer study of Ce3+ ion substituted SrFe12O19 nanohexaferrites
Ceram. Int.
Surface spin-glass in cobalt ferrite nanoparticles dispersed in silica matrix
J. Magn. Magn. Mater.
Superspin glass behavior of self-interacting CoFe2O4 nanoparticles
J. Alloys Compd
Effect of field and frequency on the temperature dependence of AC susceptibility of the (La, Gd) Ag spin-glass
Solid State Comm
Cited by (12)
High-frequency magnetic response of superparamagnetic composites of spherical Fe<inf>65</inf>Co<inf>35</inf> nanoparticles
2023, Journal of Magnetism and Magnetic MaterialsBroadband microwave magnetic and dielectric properties of (Mg<inf>0</inf><inf>·</inf><inf>6</inf>Cd<inf>0</inf><inf>·</inf><inf>4</inf>Co<inf>0</inf><inf>·</inf><inf>05</inf>Fe<inf>1</inf><inf>·</inf><inf>95</inf>O<inf>4</inf>)<inf>1-x</inf>+(MgTi<inf>2</inf>O<inf>4</inf>)<inf>x</inf> with x contents of 0.00, 0.06, 0.12, and 0.18 composites with low loss for high-frequency antennae
2023, Journal of Materials Research and TechnologyMagnetic exchange coupling and effect of grain and grain boundaries on conduction mechanism of (MgFe<inf>2</inf>O<inf>4</inf>)<inf>100-x</inf> /(BaFe<inf>12</inf>O<inf>19</inf>)<inf>x</inf> nanocomposites
2023, Ceramics InternationalCitation Excerpt :Fig. 5 (e) shows the occurrence of a broad peak in ZFC curve around (70–75) K which seems to be the blocking temperature of these NPs however the blocking temperature of hard phase is usually higher than the soft phase, and in our case, the TB of soft phase lies above the room temperature, therefore this broad peak around (70–75) K may not be attributed as the blocking peak and this peak may be attributed as the surface freezing peak which is usually observed at low temperatures in the ZFC curve. Almessiere et al. [30] also reported the TB value of hexaferrites (HFs) above the room temperature. The large magnetization difference (δM) for x = 0 is due to the soft magnetic behaviour of MgFe2O4 NPs and a sharp decrease in δM was observed with the inclusion of hard phase into the NCs as shown in Fig. 5 (f).
Synthesis of ferrite nanoparticles using sonochemical methods
2023, Ferrite Nanostructured Magnetic Materials: Technologies and ApplicationsSubstitutional effect of Ni-Al in electromagnetic properties of Sr-hexaferrite based non-rare earth magnet with high energy density for motor applications
2022, Materials Chemistry and PhysicsCitation Excerpt :The high value of (BH)max is a major challenge for this magnet, and it is associated with the increase in both remanence (Mr) and coercivity (Hc) simultaneously. In order to increase these parameters, strontium hexaferrite is extensively being explored at the nanoscale level with different synthesis methods and the substitution of various elements [9,10]. Substitution of different elements influences the anisotropic crystal structure of strontium hexaferrite (SrM) and hence the electromagnetic properties.