Peculiairities of Magnetic Properties of the Garnet Y2.25Gd0.75Fe5O12 Irradiated by Fast Neutrons

Abstract

Polycrystalline yttrium‐gadolinium iron garnet samples irradiated by different fluences of fast neutrons ((0 to 2.0) × 1024 m—2 were investigated by magnetic and X‐ray methods. Irradiation was found to increase the temperature of sublattice magnetization compensation from 5 to 47 K. The increase was attributed to the different behaviour of gadolinium and iron sublattices under irradiation. In the irradiated samples negative magnetization states were found to arise in the vicinity of the compensation point. The phase H—T diagram of such states was plotted based on the measurements performed. The cause of a negative magnetization occurrence was shown to be the intersection of a spin reorientation with respect to temperature in the compensation point and a freezing of magnetic moments of ferrimagnetic clusters in a spin‐glass matrix.

Element-specific magnetometry on negatively magnetized NdMnO3+δ

“…4 In the last years, negative magnetization has been found in non-stoichiometric NdMnO 3+␦ , 5 and Nd 1−x Ca x MnO 3 , 6 among other manganites. [7][8][9][10][11] All of these systems are complex ferri-or canted antiferromagnetic ͑AF͒ systems with at least two magnetic sublattices and some degree of disorder ͑structural or chemical͒.…”

Phase segregation in the hole-doped manganite Nd0.93MnO2.96: magnetic measurements and neutron diffraction

“…If, beside d-d interactions of manganese ions exist f-d and f-f interactions of rare-earth ions, the magnetic behavior of RMnO 3 perovskites becomes much more complicated. For instance the perovskite Gd 0.55 Ba 0.45 MnO 3Àd , where dp0.37 orders below the Neel temperature T N =160 K and as some oxides and molecular magnets [10,11] exhibits a negative magnetization that appears below a compensation point T cp =90 K, due to Gd sub-lattice magnetic contribution [12]. For the stoichiometric NdMnO 3 compound, conclusions about Nd magnetic behavior are conflicting.…”

Strain effect on orbital and magnetic structures of Mn ions in epitaxial Nd0.35Sr0.65MnO3/SrTiO3 films using X-ray diffraction and absorption

“…The negative magnetization may be attributed to the coupling between the FM of Nd and the FM- c AFM of Mn phases. This phenomenon was usually observed in complex ferri- or c AFM-systems 35,36 , and was further discussed comprehensively using an O 2 p itinerant electron model for such magnetic oxide systems 37–39 . In addition, Alexandrov et al .…”