ZnFe₂O₄: Rapid and sub-100 °C synthesis and anneal-tuned magnetic properties

Abstract

Nanocrystalline zinc ferrite (ZFO) has been synthesized from metal acetylacetonates by microwave irradiation for 5 min in the presence of a surfactant. The as-prepared material is ZFO and has been subjected in air to conventional furnace annealing and to rapid annealing at different temperatures. Both annealing protocols lead to well-crystallized ZFO, with crystallite sizes in the range $8-20 nm, which is ferrimagnetic, even at room temperature, with magnetization attaining saturation. While the magnetization M S of conventionally annealed ZFO varies with crystallite size in the expected manner, rapid annealing leads to high M S even when the crystallite size is relatively large. The coercivity is greater in the conventionally annealed ZFO. Thermal and magnetic measurements suggest that the inhomogeneous site cationic distribution within each crystallite caused by rapid annealing can be used to tailor the magnetic behaviour of nanocrystalline ferrites.

Cr‐doped ZnAl2O4: Microwave solution route for ceramic nanoparticles from metalorganic complexes in minutes

“…Generally, the synthesis of a crystalline ceramic such as ZnAl 2 O 4 requires high temperatures and/or long durations. The present work demonstrates that microwave irradiation can be used to synthesize fine‐grained refractory oxides at temperatures as low as 220°C relatively quickly (40‐60 minutes), the rapidity stemming from the dielectric heating at the molecular level that leads to uniform heating and high local temperatures . Considering that the material is a ceramic, 220°C is quite low (compared to co‐precipitation method) for synthesizing crystalline material and much faster compared to other methods.…”

“…Synthesis of ceramics using this method was first attempted by Komarneni et al This technique is advantageous over conventional methods because of: (i) high reaction rates; (ii) excellent control over reactions; (iii) higher yields; and (iv) improved reproducibility . Though there are a few reports describing the microwave synthesis of spinel oxides, the processes described are either lengthy or highly pH‐sensitive. Further, the synthesis of transition metal‐doped ZnAl 2 O 4 nanoparticles using this method has not been reported.…”

Low-Thermal-Budget Solution Processing of Thin Films of Zinc Ferrite and Other Complex Oxides

“…Additionally, toxic solvents and additives should be avoided. In this regard, microwave chemistry is promising and has recently been applied to the synthesis of ferrite nanoparticles, too [7]. It is important to note that microwave irradiation provides a selective heating tool, which means that substances with different microwave absorbing properties will be heated unequally.…”

Therapeutic Significance of 1,4-Dihydropyridine Compounds as Potential Anticancer Agents

“…In continuation of our ongoing research work on microwave assisted synthesis of nano materials [11,12] we have found that, nano-crystalline metal oxides have attracted considerable attention of synthetic and medicinal chemists because of their high catalytic activity and reusability [13][14][15][16][17][18][19][20][21][22][23][24][25]. Zinc oxide is an inexpensive, moisture stable, reusable, commercially available and is non-toxic, insoluble in polar as well as non-polar solvents [26][27][28][29][30][31].…”