Gd(Mn1−xInx)2: crystal structure and physical properties (original) (raw)
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Structure and magnetic properties of Gd4(Mn0.05Sb0.95)3
Physica B: Condensed Matter, 2003
This work studies the structure and magnetic properties of Gd 4 (Mn 0.05 Sb 0.95 ) 3 with the aim to clarify the role played by the magnetic Mn atom. Upon substitution of Mn for Sb in the parent Gd 4 Sb 3 compound, it is found that the inverted Th 3 P 4 -like structure has been somewhat expanded. The Curie temperature is increased while magnetic moment, measured in the field of 50 kOe at 200 K, is slightly reduced. The ferromagnetic semiconductor, Gd 4 (Mn 0.05 Sb 0.95 ) 3 , undergoes a ferromagnetic to paramagnetic transition at 270 K. Observed anomalies occur in the magnetization vs. temperature curves measured in a very low magnetic field. They are attributed to magnetic inhomogeneities resulting from a structural modification in Gd 4 (Mn 0.05 Sb 0.95 ) 3 . r 2002 Elsevier Science B.V. All rights reserved. PACS: 75.50.Pp; 75.30.Cr Keywords: Gd 4 (Mn 0.05 Sb 0.95 ) 3 ; Structure; Inhomogeneity; Magnetic phase transition 0921-4526/03/$ -see front matter r 2002 Elsevier Science B.V. All rights reserved. PII: S 0 9 2 1 -4 5 2 6 ( 0 2 ) 0 1 7 7 5 -1
Magnetic properties of Gd1−xCexMn2Ge2 compounds
Solid State Communications, 2001
The crystal structure and magnetic properties of polycrystalline Gd 12x Ce x Mn 2 Ge 2 (x 0:0 2 1:0) compounds with the ThCr 2 Si 2 -type structure have been investigated and the magnetic phase diagram has been constructed. The ferromagnetism observed in CeMn 2 Ge 2 transforms to ferrimagnetism with the substitution of Gd for Ce. An additional high temperature ferromagnetic phase in GdMn 2 Ge 2 weakens and eventually disappears with the addition of Ce. The saturation magnetization with increasing x at 4.2 K decreases up to the x 0:5, and then increases again. q
ChemInform Abstract: Magnetism and Hyperfine Interactions in Gd2Ni2Mg
ChemInform, 2001
Gd 2 Ni 2 Mg was synthesised by reaction of the elements in a sealed tantalum tube in a high-frequency furnace. The structure was investigated by single crystal X-ray diffraction: Mo 2 FeB 2 type, P 4/mbm, a = 743.8(1), c = 375.3(1) pm, wR 2 = 0.0560, 256F 2 values, 12 variables. The Gd 2 Ni 2 Mg structure is an intergrowth of distorted AlB 2 and CsCl slabs of compositions GdNi 2 and GdMg. The magnetic phase transitions were studied by AC and DC magnetic susceptibility measurements and 155 Gd Mössbauer spectroscopy. Antiferromagnetic ordering is detected at T N = 49.00(5) K followed by two further transitions at T f1 = 20.70(5) and T f2 = 4.5(1) K, respectively. Non-vanishing second and third harmonic components of the induced voltage under application of a small AC magnetic field reveal the ferromagnetic nature of the second transition at T f1 . Below T f1 , Gd 2 Ni 2 Mg shows strong irreversibility between field cooled (FC) and zero field cooled (ZFC) DC magnetization and magnetic hysteresis behaviour. 2001 Éditions scientifiques et médicales Elsevier SAS. All rights reserved.
Acta Chimica Slovenica
The phase equilibria in the MnGa 2 Tе 4-MnIn 2 Tе 4 system were experimentally investigated by means of differential thermal analysis and powder X-ray diffraction technique. It was found that this system is quasi-binary and characterized by dystectic and eutectic equilibria and the formation of a wide area of solid solutions based on the starting compounds. The crystal structures of the MnGaInTe 4 and MnIn 2 Tе 4 were refined by the Rietveld method using powder X-ray diffraction data. It was established, that both phases crystallize in the tetragonal system (Space group I-42m). Electron paramagnetic resonance and Raman spectra, as well as the temperature dependences of the electrical conductivity and the Hall effect for the MnGaInTe 4 crystal, were studied.
Journal of Alloys and Compounds, 2009
In this paper, we present crystal structure, electronic structure and magnetic properties of pollicrystalline Gd(Ni 1−x Fe x ) 3 intermetallic compounds. The rhombohedral PuNi 3 type of crystal structure for the whole series was confirmed with the use of X-ray powder diffraction. The partial replacement of Ni by Fe atoms up to x ≤ 0.4 causes the increase in Curie temperature T C and next for 0.4 < x ≤ 1 a slow decrease in T C value. As it was also shown saturation magnetization of the examined samples monotonically decreases with increasing Ni/Fe substitution. The magnetocaloric effect (MCE) for several samples with T C values around the room temperature was estimated from magnetic isotherms. The decrease in magnetic entropy connected with the increase in magnetic disorder in 3d magnetic sublattice has been observed. Moreover some correlations between magnetic properties and electronic structure studied by X-ray photoemission spectroscopy (XPS) have been found.
Physical Review B, 2020
GdNi is a ferrimagnetic material with a Curie temperature TC = 69 K which exhibits a large magnetocaloric effect, making it useful for magnetic refrigerator applications. We investigate the electronic structure of GdNi by carrying out x-ray absorption spectroscopy (XAS) and x-ray magnetic circular dichroism (XMCD) at T = 25 K in the ferrimagnetic phase. We analyze the Gd M4,5-edge (3d-4f) and Ni L2,3-edge (2p-3d) spectra using atomic multiplet and cluster model calculations, respectively. The atomic multiplet calculation for Gd M4,5-edge XAS indicates that Gd is trivalent in GdNi, consistent with localized 4f states. On the other hand, a model cluster calculation for Ni L2,3-edge XAS shows that Ni is effectively divalent in GdNi and strongly hybridized with nearest neighbour Gd states, resulting in a d-electron count of 8.57. The Gd M4,5-edge XMCD spectrum is consistent with a ground state configuration of S = 7/2 and L=0. The Ni L2,3-edge XMCD results indicate that the antiferromagnetically aligned Ni moments exhibit a small but finite total magnetic moment (mtot ∼ 0.12 µB) with the ratio mo/ms ∼ 0.11. Valence band hard x-ray photoemission spectroscopy shows Ni 3d features at the Fermi level, confirming a partially filled 3d band, while the Gd 4f states are at high binding energies away from the Fermi level. The results indicate that the Ni 3d band is not fully occupied and contradicts the charge-transfer model for rare-earth based alloys. The obtained electronic parameters indicate that GdNi is a strongly correlated charge transfer metal with the Ni on-site Coulomb energy being much larger than the effective charge-transfer energy between the Ni 3d and Gd 4f states.
Magnetism and hyperfine interactions in Gd2Ni2Mg
Solid State Sciences, 2001
Gd 2 Ni 2 Mg was synthesised by reaction of the elements in a sealed tantalum tube in a high-frequency furnace. The structure was investigated by single crystal X-ray diffraction: Mo 2 FeB 2 type, P 4/mbm, a = 743.8(1), c = 375.3(1) pm, wR 2 = 0.0560, 256F 2 values, 12 variables. The Gd 2 Ni 2 Mg structure is an intergrowth of distorted AlB 2 and CsCl slabs of compositions GdNi 2 and GdMg. The magnetic phase transitions were studied by AC and DC magnetic susceptibility measurements and 155 Gd Mössbauer spectroscopy. Antiferromagnetic ordering is detected at T N = 49.00(5) K followed by two further transitions at T f1 = 20.70(5) and T f2 = 4.5(1) K, respectively. Non-vanishing second and third harmonic components of the induced voltage under application of a small AC magnetic field reveal the ferromagnetic nature of the second transition at T f1 . Below T f1 , Gd 2 Ni 2 Mg shows strong irreversibility between field cooled (FC) and zero field cooled (ZFC) DC magnetization and magnetic hysteresis behaviour. 2001 Éditions scientifiques et médicales Elsevier SAS. All rights reserved.