Magnetic study of M-type doped barium hexaferrite nanocrystalline particles

Abstract

Co-Ti and Ru-Ti substituted barium ferrite nanocrystalline particles BaFe 12-2x ) were prepared by ball milling method, and their magnetic properties and their temperature dependencies were studied. The zero-field-cooled (ZFC) and field-cooled (FC) processes were recorded at low magnetic fields and the ZFC curves displayed a broad peak at a temperature T M . In all samples under investigation, a clear irreversibility between the ZFC and FC curves was observed below room temperature, and this irreversibility disappeared above room temperature. These results were discussed within the framework of random particle assembly model and associated with the magnetic domain wall motion. The resistivity data show some kind of a transition from insulator to perfect insulator around M T . At 2 K, the saturation magnetization slightly decreased and the coercivity dropped dramatically with increasing the Co-Ti concentration x. With Ru-Ti substitution, the 2 saturation magnetization showed small variations, while the coercivity decreased monotonically, recording a reduction of about 73% at x = 0.6. These results were discussed in light of the single ion anisotropy model and the cationic distributions based on previously reported neutron diffraction data for the CoTi substituted system, and the results of our Mössbauer spectroscopy data for the RuTi substituted system.

Magnetic study of M-type Ru–Ti doped strontium hexaferrite nanocrystalline particles

“…For each substituted sample the ZFC magnetization increased from almost the same value of~2 emu/g at 5 K to a maximum value at T M , and then decreased exhibiting a broad peak. Similar magnetization behavior was reported for BaM doped with both CoeTi and RueTi [41]. The temperature at peak value increased with increasing x.…”

“…7, the temperature dependence of the electrical resistivity SrFe 12À2x Ru x Ti x O 19 with x ¼ 0.2, measured in zero magnetic field and in 1 T is shown. Similar behaviors were reported recently for BaM doped with both RueTi and CoeTi substitutions [41]. No significant magnetic field effects (magnetoresistance) were observed and the resistivity data show some kind of a transition from insulator to perfect insulator below T M .…”

“…No significant magnetic field effects (magnetoresistance) were observed and the resistivity data show some kind of a transition from insulator to perfect insulator below T M . The resistivity behavior could be associated with a perfectly insulating ferroelectric phase below about 50 K, which is destroyed as the conductivity rises above this temperature [41]. Fig.…”

Optical and Multiferroic Properties of Gd‐Co Substituted Barium Hexaferrite

“…[15,16] Many routes are available to synthesize BaM such as ball milling, laser evaporation method, emulsion method, sol gel method. [17][18][19][20][21][22][23][24][25][26][27] The optimal technique, the sol gel method is advanced and offers low DOI: 10.1002/crat.201700098 temperature, procedural simplicity, decent yield, uniform crystallite size and low operational cost.…”

Synthesis and Magnetic Properties of (Zn²⁺Ti⁴⁺) Substituted W-type and Y-type Ferrites

“…In addition, many research groups have investigated barium ferrite as microwave absorbers 6)- 8) and magnetic recording media 9) by modifying its anisotropy. The control of its magnetic property is achieved by the replacement of Fe 3+ ions by Al 3+ 10)-13) , Cr 3+ 13)-15) ions or pairs of (Me 2+ Mt 4+ ) ions such as (Co 2+ Ti 4+ ) 16,17) , (Zn 2+ Ti 4+ ) 18), 19) , (Mn 2+ Ti 4+ ) 6), 20) , (Ni 2+ Sn 4+ ) 21) , (Co 2+ Sn 4+ ) 22) , (Co 2+ Zr 4+ ) 23), 24) , where the Me and Mt represent divalent and tetravalent cations, respectively. The substitution effect on anisotropy is so significant that even the hard magnetic property of BaFe12O19 was changed to soft magnetic by substitution of (Co 2+ Zn 2+ )Ti 4+ for Fe 3+ 25) .…”