The Influence of Yb Substitution on the Magnetic, Electric Properties and Electronic Structure of YbxGd1-xNi5 System

The crystal and electronic structure, magnetic and electric properties of intermetallic compounds YbxGd1¡xNi5 (x = 0:0, 0.2, 0.4, 0.5) are presented. The whole series crystallize in the hexagonal CaCu5 type of crystal structure. The ordering temperatures TC and the e®ective magnetic moments decrease with increase in ytterbium concentration. The electronic structure studied by X-ray photelectron spectroscopy method shows the domination of Ni 3d states nearby the Fermi level. The multiplet structure visible in valence bands is typical of Yb3+ ions

Influence of transition metal substitution on the low-field magnetic properties in the Gd(Ni1-xTx)3 (T = Fe, Co) intermetallic compounds

The low-field magnetic properties of polycrystalline Gd(Ni1 xTxq3 (T = Fe, Co) intermetallic compounds are presented. The whole system crystallizes in the rhombohedral PuNi3 type of crystal structure. The composition dependence of the Curie temperature TCpxq is associated with the change in the number of 3d electrons. Moreover, the field cooled and zero field cooled (FC-ZFC) curves at low applied magnetic field are related to the anisotropy of T element. The saturation magnetic moment MSpxq upon doping was estimated based on the hysteresis loops MpHq[…

Hyperfine interactions in RxGd1- xFe3 intermetallics R = Tb, Y

The structural and magnetic properties of rare earth iron intermetallic compounds TbxGd1-xFe3 and YxGd1-xFe3 (x = 0. 0, 0. 1, 0. 2, 0. 4, 0. 5, 0. 6, 0. 8, 1. 0) was studied by X-ray diffraction, the 57Fe Mössbauer effect and SQUID measurements. All investigated compounds crystallize in the rhombohedral PuNi3-type of crystal structure. The investigation of magnetic properties of RxGd1-xFe3 proved their ferrimagnetic behavior. The Curie temperature of the investigated compounds decreases with the increase of R concentration from 721K (GdFe3) to 655K (TbFe3) and 533K (YFe3). The saturation magnetic moment MS in the RxGd1-xFe3 system increase with x parameter. The Mössbauer spectra are analyzed using four sextets, corresponding to three crystallographically (b, c, h) and four magnetically (b, c, h1, h2) inequivalent sites for iron. The mean hyperfine magnetic field increases with increase of the Gd concentration

Influence of cr-atoms on the magnetic and electrical properties in Ho(Co1-xCrx)2 compounds

AC magnetic susceptibility, electrical resistivity and X-ray Photoelectron Spectroscopy (XPS) measurements have been performed on the Ho(Coi_a,Cra,)2 compounds with x=0.0, 0.03, 0.05, 0.10, 0.15 and 0.20. A strengthening of the HoCo2 ferrimagnetism shows up through a rapid increase at small Cr concentration x of the Curie temperature Tq which reaches a maximum around x= 0.15. The lattice parameters also go through a maximum for the same concentration of Cr. A remarkable decrease of the density of states near the Fermi level is observed for the sample with x= 0.20. We correlate the changes of the Curie temperature with the decrease of d-electron concentration when Cr substitutes for Co[…

Effect of Tb/Gd substitution on crystal structure and exchange interactions of Gd1- xTb xNi 3 intermetallic compounds

In the paper an in uence of Tb/Gd substitution on crystal structure and exchange interactions of Gd1xTbxNi3 (x = 0:0, 0.5, 0.8, 1.0) polycrystalline compounds have been studied. The crystal structure of all samples was checked at the room temperature by means of X-ray di raction. Exchange integrals of R R (JRR), T T (JTT) and R T (JRT) atoms were evaluated from M(T) magnetization curves (2 300 K, 2 T) based on the mean eld theory calculation. As it was shown the samples examined are single phase and crystallize in the PuNi3 (space group R-3m) type of crystal structure. The Tb/Gd substitution causes the decrease of lattice parameters as well as the volume of the unit cell. With increase of the x parameter the magnetic moment of Tb atoms increases from 6.94 B (x = 0:5) to 8.12 B (x = 1). The M(T) dependence of the examined compounds depends almost 8 times stronger on exchange interactions within the R R site than the interactions between the two antiferromagnetically coupled magnetic sublattices R T

Effect of alloying on magnetism and electronic structure of Gd(In1-xSnx)3 system - Ab initio study

We present the results of ab initio study of electronic and magnetic properties of Gd(In1xSnx)3 alloys carried out with the use of FP-LAPW method. Our precise ab initio calculations for the rst time uniquelly con rmed experimentally based predictions that the ground state magnetic structure of the alloys is antiferromagnetic and that upon the In/Sn substitution the magnetic structure undergo transition, changing the antiferromagnetic ordering from the ( 00)-type for the GdSn3 compound to the ( 0)-type for the GdIn3 one. Moreover, calculations gave an explanation of the oscillatory variation of density of states at Fermi level indicated by XPS measurements

Corrosion study of resorbable Ca60Mg15Zn25 bulk metallic glasses in physiological fluids

The corrosion activity of amorphous plates of Ca60Mg15Zn25 alloy was investigated. The biocompatible elements were selected for the alloy composition. The electrochemical corrosion and immersion tests were carried out in a multi-electrolyte fluid and Ringer's solution. Better corrosion behavior was observed for the samples tested in a multi-electrolyte fluid despite the active dissolution of Ca and Mg in Ringer's solution. The experimental results indicated that reducing concentration of NaCl from 8.6 g/dm3 for Ringer's solution to 5.75 g/dm3 caused the decrease of the corrosion rate. The volume of the hydrogen evolved after 480 min in Ringer's solution (40.1 ml/ cm2) was higher in comparison with that obtained in a multi-electrolyte fluid (24.4 ml/cm2). The values of opencircuit potential (EOCP) for the Ca60Mg15Zn25 glass after 1 h incubation in Ringer's solution and a multielectrolyte fluid were determined to be −1553 and −1536 mV vs. a saturated calomel electrode (SCE). The electrochemical measurements indicated a shift of the corrosion current density (jcorr) from 1062 μA/cm2 for the sample tested in Ringer's solution to 788 μA/cm2 for the specimen immersed in a multi-electrolyte fluid. The corrosion products analysis was conducted by using the X-ray photoelectron spectroscopy (XPS). The corrosion products were identified to be CaCO3, Mg(OH)2, CaO, MgO and ZnO. The mechanism of corrosion process was proposed and described based on the microscopic observations. The X-ray diffraction and Fourier transform infrared spectroscopy (FTIR) also indicated that Ca(OH)2, CaCO3, Zn(OH)2 and Ca(Zn(OH)3)2·2H2O mainly formed on the surface of the studied alloy.The work was supported by National Science Centre under research project no.: 2013/09/B/ST8/02129

Electrical resistivity and electronic structure of the Tb xGd 1-xNi 3 system

In the paper the electric properties and electronic structure of the intermetallic TbxGd1xNi3 compounds are presented. The partial replacement of Gd by Tb atoms causes the decrease of the Curie temperature (TC) and the increase of the residual resistivity. According to the Matthiessen rule the scattering mechanisms in (T) have been analyzed. Moreover, the reduced form of the electrical resistivity Z(T T0) indicates a deviation from the linearity for x > 0:2. This kind of behaviour can be attributed to density of d states near by the Fermi level (EF) which are dominated by Ni 3d states. The valence band spectra as well as the core level lines have been analyzed as the in uence of Tb/Gd substitution on the electronic structure

Magneto-history effect in the Tb xGd 1-xNi 3 Compounds

The compounds TbxGd1xNi3 with a PuNi3-type structure have been obtained. The magnetic properties have been investigated by using SQUID magnetometer (Quantum Design MPMS, temperature from 1.9 K to 300 K and magnetic eld up to 7 T). The partial replacement of Gd by Tb atoms is re ected in a decrease of the ordering temperature from 115 K (x = 0:0) to 81 K (x = 1:0) as well as the increase of the saturation magnetic moment MS from 6.93 B/f.u. (x = 0:0) to 7.14 B/f.u. (x = 1:0). A large di erence of M(T) curves has been noticed between the so-called eld cooling zero eld cooling magnetization. The thermomagnetic curves are sensitive to the applied magnetic eld and their origin can be understood as the domain-wall pinning e ect and as the temperature dependence of coercivity

The Electronic and Magnetic Properties of YbxGd1-xNi5 Systems

The intermetallic compounds YbxGd1¡xNi5 crystallize in the hexagonal CaCu5-type structure. Based on wide ranging SQUID-type magnetometer, it was shown that the saturation magnetization decreases with growing concentration of ytterbium. The opposite tendency was observed for the Sommerfeld coefficient obtained in the heat capacity measurements. These results are confirmed using ab initio band structure calculations