Magnetic and optical properties of multiferroic GdMnO3 nanoparticles

Abstract

The magnetic and optical properties of multiferroic GdMnO 3 nanoparticles synthesized by a polymerized complex method have been investigated. The GdMnO 3 nanoparticles crystallized in orthorhombic perovskite-type structure. The zero-field-cooled and field-cooled magnetizations show that complicated magnetic transitions occur in a temperature range from 2 to 60 K, which were confirmed by magnetic hysteresis loops. Three shoulder absorption peaks centered at about 2.0, 2.3, and 2.7 eV are attributed to the Mn ͑3d͒-electronic transitions, while an absorption peak at around 4.1 eV corresponds to the charge-transfer transitions between O ͑2p͒ and Mn ͑3d͒ states. UV emission at about 396 and 406 nm and blue emission at around 466 nm have been found, which may be attributed to the spin-allowed charge-transfer transitions.

Infrared Active Phonons and Optical Band Gap in Multiferroic GdMnO3Studied by Infrared and UV-Visible Spectroscopy

“…The obtained value is quite approximate as observed for polycrystalline YMnO 3 [32] and YMn 2 O 5 [33]. Recently, polycrystalline GdMnO 3 synthesized by sol-gel technique have been reported with the optical band gap of ≈ 2.9 eV [34], which is larger than our results as well as already reported by Wang et al [30].…”

“…Also, three strong absorption peaks centered at 455 nm (2.7 eV), 505 nm (2.4 eV) and 612 nm (2.0 eV) indicated as arrows in Fig. 5 may be attributed to the Mn (3d)-electronic transitions in consistency with the reported behaviour [30]. The optical bandgap energy of GMO is estimated by using the Tauc relation [31]:…”

Thermal, Magnetic and Electrical Properties of Multiferroic GdMnO3Nano Particles by a Co-Precipitation Method

“…The Complex magnetic transition of GdMnO 3 nano particles verified by the hysteresis loops of GdMnO 3 nano-particles recorded at different temperatures 20 K, 40 K, 60 K, 80 K and 100 K respectively as shown in Fig. 7 which shows the paramagnetic behavior of the GdMnO 3 nano particles is found in the loops at above 80 K. With a decrease in temperature, an antiferromagnetism is observed at 65 K and further decrease of the temperature, a weakferromagnetic behavior is found at 20 K, due to the contribution of the net moment of the Gd spins is larger than that of the antiferromagnetically canted state of the Mn spins, giving rise to a ferromagnetic like loop because the external magnetic field aligns the Gd moments [37].…”

Dielectric relaxation in glass and glass‐ceramic materials of the system La2O3‐Gd2O3‐PbO‐MnO‐B2O3

“…Colossal magnetoresistance has been observed in the La 1‐y Pb y MnO 3 phase . Gd 2 O 3 was added to the composition because of the interesting multiferroic properties of the GdMnO 3 phase, and its ferroelectric behavior at room temperature associated with the frequency independent dielectric anomaly at 373 K . Gd‐doped LaMnO 3 has a very complicated behavior, depending on the doping concentration and temperature, and it can be either an antiferromagnetic insulator or a ferromagnetic metal.…”