Magnetic resonance was studied in magnetic fields parallel or perpendicular to the film plane in magnetron-sputtered [Co(8 Å)/Cu(dCu)(111)]20 multilayers. Oscillations of the magnetic anisotropy KA and the width ΔHres of the resonance line as a function of the thickness of the copper interlayers were found in the interval dCu=7–19 Å. Extrema of KA and ΔHres were observed at dCu=nd(111), where n is an integer or half-integer, and d(111)=2.087 Å—the distance between the (111) planes in Cu. In addition, the distances between the neighboring maxima or minima were 1, 1.5, and 2d(111). The KA and ΔHres oscillations occurred synchronously with oscillations of the resistivity at saturation (in the field H=15 kOe) and oscillations of the magnetoresistance. An interlayer antiferromagnetic exhange interaction was found in the ranges dCu=8–11 Å and dCu⩾18 Å. The effects observed were due to nonmonotonic variation of the interlayer interface roughness with increasing dCu.
In this work the EPR spectrum of copper orotate single crystals Cu(C5H2N2O4)(H2O)2 was investigated. At room temperature the EPR spectrum of copper orotate has a single line with rhombic anisotropy. The extremal values of effective g-factor were obtained. The low-temperature broadening of resonance line which may be connected with short-range magnetic order was established.The orotic acid is the predecessor of the pyrimidine bases of nucleic acids at their biosynthesis. The biotransformational reactions of an orotic acid are realized in the presence of enzyme. The metal ions are necessary for their activation and normal functioning. Series of works [1-2] devoted to the interaction of metal ions with orotic acid and its derivatives has been recently published. The main attention was given to the interrelation between chemical properties of metal ions and their role in life of organism.Copper orotate [Cu(C 5 H 2 N 2 O 4 )(H 2 O) 2 ] belongs to the family of metallo-organic substances used in medicine as complexes, having enzyme properties. For finding out the general laws of reactions with enzyme the establishment of metal-organic complexes equilibrium structures is necessary. Thus, the most of information we obtained from the study of EPR spectra of Cu 2+ ions in similar metal-organic complexes.In this paper we report the measurements of angular and temperature dependences of EPR spectrum of Cu 2+ ions in a copper orotate single crystal. Because of the weak bond between molecules in a crystal it is possible to assume small distinction in coordination of Cu 2+ ions in crystals of orotic acid salts and biological solution [3]. Therefore it is possible to consider that Cu 2+ ions spectra in crystal and biological solution are identical.Blue-green colored single crystals of copper orotate belong to monoclinic space group P2 1 /n with parameters a = 9.503Å, b = 6.9147Å, c = 11,851Å, β = 95.22 o , z = 4, V = 775.5Å 3 . The parameters of unit cell and intensity of reflections are measured on an automatic diffractometer Siemens P3/PC [4]. From the analysis of * ) Presented at 12
An x-ray diffraction study and measurements of the EPR spectrum of a copper orotate single crystal [Cu(C5H3N2O4)(H2O)2] are carried out. At room temperature a one-center EPR spectrum of orthorhombic symmetry is observed. The extremal values of the g factors are determined. Low-temperature broadening of the resonance lines is observed. It is assumed that it is due to the formation of short-range antiferromagnetic order, which arises when the temperature approaches the Néel point TN=3.2 K.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.