7.8.3 Mössbauer spectra, saturation magnetization, spectroscopic splitting factor, and Curie temperature

Author(s):  
H.P.J. Wijn
2009 ◽  
Vol 152-153 ◽  
pp. 49-53
Author(s):  
V.V. Serikov ◽  
N.M. Kleinerman ◽  
N.V. Volkova ◽  
N.I. Kourov

The Mössbauer spectra of PdMnxFe1-x alloys obtained at 80 K and at 300 K were studied in the 0.2 < x < 0.8 concentration range, in which there realizes a microinhomogeneous multiphase medium formed by isostructure phases of the constituent compositions: ferromagnetic PdFe (ТС=730 К) alloy undergoing atomic ordering and antiferromagnetic PdMn (TN=815 К) intermetallic compound. Magnetic properties studies evidence the presence of a third presumably noncollinear phase with its own ordering temperature lying below the Curie temperature of the ferromagnetic phase in the 0.2 < x < 0.8 concentration range. The Mössbauer spectra at 300 K exhibit a doublet for antiferromagnetic alloys (x > 0.8) and a sextet at Hhf ~350 kOe for ferromagnetic alloys (x < 0.2). In the intermediate concentration range several peaks 0 < Hhf < 350 kOe have been observed in the P(Hhf) curves, which result from microinhomogeneous multiphase state.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Yun He ◽  
Xingxing Yang ◽  
Jinpei Lin ◽  
Qing Lin ◽  
Jianghui Dong

Zinc substituted magnesium ferrite nanomaterialsMg1-xZnxFe2O4(x= 0, 0.1, 0.3, 0.5, 0.7) powders have been prepared by a sol-gel autocombustion method. The lattice parameter increases with increase in Zn concentration, but average crystallite size tends to decrease by increasing the zinc content. SEM results indicate the distribution of grains and morphology of the samples. Some particles are agglomerated due to the presence of magnetic interactions among particles. Room temperature Mössbauer spectra ofMg1-xZnxFe2O4shows that the A Mössbauer absorption area decreases and the B Mössbauer absorption area increases with zinc concentration increasing. The change of the saturation magnetization can be explained with Néel’s theory. It was confirmed that the transition from ferrimagnetic to superparamagnetic behaviour depends on increase in zinc concentration by Mössbauer spectra at room temperature. Saturation magnetization increases and coercivity decreases with Zn content increasing.


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