The effect of small additions of yttrium, lanthanum, and cerium oxides on some magnetic characteristics of magnesium-manganese ferrites and the X-ray spectra of transition metals in them
The isotypic ternary compounds Ba3[MoN4] and Ba3[WN4] were prepared by reaction of the transition metals with barium (Ba3N2, resp.) under nitrogen. The crystal structures were determined by single crystal X-ray diffraction: Ba3[MoN4] (Ba3[WN4]): Pbca; Z = 8; a = 1083.9(3) pm (1091.8(3) pm), b = 1030.3(3) pm (1037.5(3) pm), c = 1202.9(3) pm (1209.2(4) pm). The structures contain isolated tetrahedral anions [MN4]6- (M = Mo, W) which are arranged in form of slightly distorted hexagonal layers and which are stacked along [010] with the sequence (···AB···). Two of the three Ba atoms are situated between, the third one is placed within the layers of [MN4]-groups. In this way the structures can be derived from the Na3As structure type.
AbstractThe magnetic characteristics of the dilute magnetic system GaGdN are investigated by mainly soft-X-ray magnetic circular dichroism (MCD) in energy range of 1160 – 1240 eV. The strong MCD signals up to 30 % at 15K are observed. The temperature dependence of its intensity is not on simple Curie-Weiss curve and depicts three-step curve. A step around 40 – 100K suggests a new magnetic phase. The luminescence spectrum of GaGdN at low temperature is divided into three parts consisting of two broad bands around 432 nm and 503 nm and a sharp peak at 652 nm. This sharp line is assigned to the intra-transition of f – f orbital owing to the weak temperature dependence of the intensity and peak position. AlGdN grown by molecular beam epitaxy produces luminescence at 318.5 nm. X-ray absorption fine structure is examined to survey the occupancy of the Gd ion in the grown specimens.
The coordination chemistry of butane-2,3-dione bis (2′-pyridylhydrazone) towards the divalent first-row transition metals zinc and iron has been explored. Depending upon the conditions, the ligand in the six complexes was found to be either neutral, mono, or doubly deprotonated. The zinc(II) and iron(II) complexes were fully characterized by elemental analysis, mass spectrometry, and X-ray diffraction methods.
An N4-Tetradentate Hydrazone Ligand That Binds in a Neutral, Mono- and Bisdeprotonated Form to Iron(II) and Zinc(II) Metal Ions