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[…

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

Electronic structure and X-ray photoelectron spectra of YNi4B compound

The electronic structure of the tern ary Y Ni4 B compoun d, crystalli zin g in the hexagonal CeCo4 B structure ( P 6= m m m space group ), was studied by X -ray photo electron spectroscopy and ab initio calculations. Core levels and the valence band were investigated. T he X- ray photo electron spectroscopy valence band is compared with that obtained from ab initi o calculations. The valence band spectrum at the Fermi level exhibits the domination of the Ni( 3 d ) states, which are hybridized with 4d states of Y and 2p states of B. The theoretical electronic specific heat coeffcient Û derived from N ( E F ) is about 11.33 mJ /(mol K 2 ) for exp erimental lattice parameters. T he calculated bulk modulus is B 0 = 1 :61632 Mbar

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

Electronic properties of CeNiAl4 based on ab initio calculations and XPS measurements

The CeNiAl4 compound crystallizes in an orthorhombic YNiAl4-type structure with a Cmcm space group. The earlier susceptibility data and X-ray photoelectron spectroscopy (XPS) suggested a localized character of the 4f states in CeNiAl4 with a valence state close to a Ce3 ion. In this work we present a combined theoretical and experimental study of the electronic structure for the Kondo dense system CeNiAl4 based on the XPS data and ab initio calculations. Using the band structure calculations the theoretical XPS valence band spectra are evaluated. Below the Fermi energy the total density of states contains mainly 3d states of Ni hybridized with Ce 4f states

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