Molecule Derived Synthesis of Nanocrystalline YFeO₃ and Investigations on Its Weak Ferromagnetic Behavior

Abstract

A new Y-Fe alkoxide, [YFe(OPr i ) 6 (Pr i OH)] 2 , is used in the sol-gel process to obtain the orthoferrite, YFeO 3 . The Y/Fe stoichiometry (1:1) and Y-O(R)-Fe chemical links in the single molecular precursor kinetically control the formation of metastable YFeO 3 which is otherwise difficult to prepare due to the easy formation of the garnet composition, Y 3 Fe 5 O 12 . TG/DTA analysis showed the crystallization of YFeO 3 at 680 °C, which was confirmed by XRD data. The powders obtained were nanocrystalline (TEM) and the only crystalline compound present between 600 and 1300 °C was monophasic YFeO 3 . The absence of garnet and other ironcontaining residual phases observed in previous studies was confirmed by temperaturedependent Mo ¨ssbauer and magnetization measurements. The magnetization data support a weak ferromagnetic behavior and reveal low-and high-field regimes in M-T and M-H curves, corresponding to magnetocrystalline and antisymmetric-exchange anisotropy, respectively.

Temperature dependent dielectric and magnetic properties of GdFe1−xNixO3 (0.0 ≤ x ≤ 0.3) orthoferrites

“…The corecivity enhancement at 300 K as compared to 80 K for all the samples can be attributed to the thermal dependence of anisotropy field and exchange field as reported by Mathur et al in YFeO 3 . 30 The observed increase in corecivity with doping can be due to change in magnetocrystalline anisotropy induced by variation in bond angles, bond lengths, and exchange energy. Similar type of corecivity enhancement in doped orthoferrites induced by variation in internal stresses has also been reported by other research groups.…”

Molecular Encoding at the Nanoscale: From Complex Cubes to Bimetallic Oxides

“…[4,9] Some examples for such single-source precursors exist already. [10][11][12][13][14][15][16] In most cases these heterometallic precursors are alkoxides and are thus very moisture sensitive. [17][18][19] Our goal is to identify a new precursor system that enables access to a large variety of nanoscaled bimetallic oxides, and at the same time is readily available and stable.…”

Synthesis YFeO₃ by salt-assisted solution combustion method and its photocatalytic activity

“…7) YFeO 3 -based catalysts have been explored for photocatalytic oxidation of organic dyes and exhibit higher visible-light photocatalytic activity than TiO 2 (P 25 ). 8)10) Furthermore, YFeO 3 has been found to be ferromagnetic, which renders a possibility for recovery of YFeO 3 with an external magnet in practical applications. 6) Up to now, various approaches have been applied to fabricate perovskite YFeO 3 , such as combustion synthesis, solgel, co-precipitation, thermal decomposition, microwave-assisted and solid state routes.…”

“…8)10) Furthermore, YFeO 3 has been found to be ferromagnetic, which renders a possibility for recovery of YFeO 3 with an external magnet in practical applications. 6) Up to now, various approaches have been applied to fabricate perovskite YFeO 3 , such as combustion synthesis, solgel, co-precipitation, thermal decomposition, microwave-assisted and solid state routes. 10)15) Most of the current approaches for synthesis of single phase perovskite YFeO 3 require the calcination process at high temperature, which leads to high energy-consumption and the growth of large size particles.…”

“…Furthermore, perovskite YFeO 3 is thermodynamically unstable and can transform to thermodynamically stable Fe 3 O 4 or Y 3 Fe 5 O 12 at high temperature, which makes the phase-selective synthesis of pure perovskite YFeO 3 a difficult task. 3) Among the various synthetic routes, solution combustion synthesis has been regarded as one of effective and economic approaches owing to its convenient processing, simple experimental setup, significant saving in time and energy and homogeneous products. 16),17) However, conventional solution combustion synthesis (SCS) of well-dispersed nanocrystalline oxide particles faces two difficulties of inhibiting particulate agglomeration and promoting phase formation.…”