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Abstract: The temperature dependence of the specific heat of the itinerant 5f-electron antiferromagnet UIrGe was studied on a single crystal in magnetic fields up to 14T applied along the principal crystallographic directions. For fields along the c-axis, evolution of T N-related magnetic specific heat (magnetic entropy) anomaly is compared with the corresponding magnetization steps. [Copyright &y& Elsevier]

Abstract: The magnetic properties of aligned powders of (U1− x Lu x )2Fe15Ge2 have been studied in order to determine the U contribution to the magnetism of U2Fe15Ge2. Dilution of U by Lu leads to a decrease of T C and of the magnetic anisotropy whereas the spontaneous magnetic moment increases. The results are discussed under the assumption of a magnetic state of U with a small moment as a result of mutual cancellation of the spin and orbital contributions. [Copyright &y& Elsevier]

Abstract We present the results of ac and dc magnetic susceptibility and isothermal magnetization measurements (T = 2–300 K) on the single crystals of a metallic kagome lattice, Tb 3 Ru 4 Al 12 , reported recently to undergo reentrant magnetism with the onset of long range antiferromagnetic order below (T N =) 22 K. The magnetization data obtained on the crystal with the c -axis orientation along magnetic-field reveal spin-glass-like characteristics near 17 K (below T N). However, for the orientation along basal plane, such glassy anomalies are not observable above 2 K. In this respect, this compound behaves like an 'anisotropic' re-entrant spin-glass. Possible implications of this finding to the field of 'geometrically frustrated magnetism' are considered. Highlights • Tb 3 Ru 4 Al 12 , is one of the rare intermetallics with kagome lattice features. • This compound exhibits Néel order at 22 K. • Spin-glass features are seen below about 17 K along c-direction only. • Anisotropic spin-glass feature is possibly due to geometrical frustration. [ABSTRACT FROM AUTHOR]

The crystal-electric field parameters are determined for the (Nd 0.5 Ho 0.5 ) 2 Fe 14 B compound by analyzing experimental magnetization curves obtained in magnetic fields up to 60 T. The values of the crystal-field parameters B 2 0 , B 4 0 , B 6 0 , B 4 4 , B 6 4 are 56.3, −73.2, −10.74, −8.9, 0 cm −1 for Nd 3+ ion and 312.38, −176.78, 89.2, −88.43, 0 cm −1 for Ho 3+ ion. The transition from the ferri-to the field-induced ferromagnetic state has been studied in detail. [ABSTRACT FROM AUTHOR]

In this work the magnetic and magnetocaloric properties of a (Nd 0.5 Pr 0.5 ) 2 Fe 14 B single crystal have been investigated in a wide range of temperatures and magnetic fields. Magnetic phase transition temperatures (spin-reorientation transition (SRT) at T SR  = 73 K and Curie point at T c  = 570 K) were determined together with the values of saturation magnetization M s and magnetocrystalline anisotropy constants K 1 and K 2 . In the vicinity of a spin-reorientation magnetic phase transition, the value of the magnetocaloric effect was determined as an isothermal magnetic entropy change (Δ S M ). The universal curve of Δ S′ (θ) around T SR under various magnetic field changes has been constructed by using a phenomenological procedure. It is found that this approach is applicable to materials with a second-order spin-reorientation phase transition. [ABSTRACT FROM AUTHOR]

The results of X-ray photoelectron spectroscopy measurements (core levels and valence bands) of R Fe 5 Al 7 ( R = Lu, Tm, Er, Ho, Dy, Tb, Gd) single crystals are presented in comparison with the results of bulk magnetization studies and electronic structure calculations. It is shown that the increase of the Curie temperature in R Fe 5 Al 7 from Tm to Gd is associated with an increase of the indirect R 4 f – Fe 3 d exchange interaction at the expense of the multiplicity 2 S + 1 (statistical weight) in the ground state 2 S +1 L J of R 3+ ions. The nonmonotonic behavior of the ferrimagnetic compensation temperature, T comp , as well as the values of the spontaneous magnetic moment, M s , and formation energy, E form , of the 4 f n levels in R metals in a series from ErFe 5 Al 7 to GdFe 5 Al 7 are explained by the difference in the quantum numbers L , J and S of the ground state of R 3+ ions, leading to a maximum value of T comp , M s and E form for the Dy-containing compound. The electronic structure of Gd/LuFe 5 Al 7 is calculated using the GGA+ U approach, on the basis of which the physical mechanism and relative strength of the interatomic R -Fe and Al-Fe interactions are considered, and also the difference in the magnetic moments of iron atoms in different structural positions is explained. [ABSTRACT FROM AUTHOR]

Ferrimagnet HoFe 6 Al 6 (tetragonal ThMn 12 -type crystal structure) has a compensation point for the Ho and Fe magnetic sublattices at a temperature close to absolute zero. The experimental study was carried out in fields up to 60 T. H-T phase diagrams and a full magnetization process along the principal crystallographic directions of a single-crystalline sample are obtained theoretically by using a model of a f-d ferrimagnet with two anisotropic sublattices, coupled by weak exchange interaction. The two first-order phase transitions, found experimentally along the [110] and [100] axes, were explained theoretically. The transition along the [110] direction occurs between noncollinear and collinear phases, it starts at the compensation point and ends at a tricritical point around 60 T. The transition along the [100] direction goes also from the point of compensation to the point of the liquid-vapor type at 40 T. This transition was shown to occur between two distinct noncollinear phases. The crucial role of the strong rare-earth anisotropy for the positions of the obtained critical points was revealed. [ABSTRACT FROM AUTHOR]

Magnetization curves of an YFe 3 single crystal were measured along the basal plane and the c-axis within the temperature range of 2–600 K. Their analysis provided temperature dependencies of the parameter p = ( M ep − M ha ) / M ep characterizing saturation magnetization anisotropy and magnetocrystalline anisotropy constants K 1 and K 2 . The latter was obtained using the modified Sucksmith-Thompson method and the numeric technique of approximation which takes into account slight misorientation between applied magnetic field and the hard magnetization axis allowing to describe magnetization curves accurately. [ABSTRACT FROM AUTHOR]

Studies by means of neutron diffraction and inelastic neutron scattering, the properties of terbium, nickel and aluminium (TbNiAl) hydrides and deuerides. What the magnetic order in intermetallic TbNiAl is based on; Examination of the localized vibrations of hydrogen in TBNiAIH1.39 using inelastic neutron scattering; Results of the study.

Studies the electrical resistivity and alternating current magnetic susceptibility of UCoA1. Description of UCoA1; Suggestion that UCoA1 has a nonmagnetic ground state; Examination of two Co-deficient single crystals UCo1-xAl1+x of slightly different compositions.

Structural changes through the first-order paramagnetic–antiferromagnetic phase transition of Dy 3 Ru 4 Al 12 at 7 K have been studied by means of X-ray diffraction and thermal expansion measurements. The compound crystallizes in a hexagonal crystal structure of Gd 3 Ru 4 Al 12 type ( P 6 3 / mmc space group), and no structural phase transition has been found in the temperature interval between 2.5 and 300 K. Nevertheless, due to the spin-lattice coupling the crystal volume undergoes a small orthorhombic distortion of the order of 2×10 −5 as the compound enters the antiferromagnetic state. We propose that the first-order phase transition is not driven by the structural changes but rather by the exchange interactions present in the system. [ABSTRACT FROM AUTHOR]

UH 3 is the first discovered material with ferromagnetism based purely on the 5 f electronic states, known for more than half century. Although the U metal is Pauli paramagnet, the reduced 5 f –5 f overlap in compounds allows for moment formation and ordering, typically if the U–U spacing exceeds the Hill limit, i.e. about 340 pm. The stable form of UH 3 , known as β-UH 3 , has rather high T C ≈170 K. Such high value is rather unusual, considering d U–U =331 pm. Properties of metastable α-UH 3 with d U–U =360 pm could be never well established. Using the fact that α-UH 3 is in fact bcc U with interstitials filled by H, we attempted to synthesize α-UH 3 starting from the γ-U alloys, with the bcc structure retained to room temperature by doping combined with ultrafast cooling. While up to 15% Zr a contamination by β-UH 3 was obtained, 20% Zr yielded single phase α-UH 3 . The T C value remains high and very similar to β-UH 3 . One can see an increase up to 187 K for 15% Zr, followed by a weak decrease. Magnetic moments remain close to 1 μ B /U atom. An insight is provided by ab-initio calculations, revealing a charge transfer towards H-1 s states, depopulating the U-6 d and 7 s states, leaving almost pure 5 f character around the Fermi level. The 5 f magnetism exhibits a high coercivity (μ 0 H c up to 5.5 T) and large spontaneous volume magnetostriction of 3.2⁎10 −3 . Even higher increase of T C , reaching up to 203 K, can be achieved in analogous Mo stabilized hydrides, which yield an amorphous structure. The compounds represent, together with known hydrides of U 6 Fe and U 6 Co, a new group of robust 5 f ferromagnets with small d U–U but high T C . Although common hydrides are fine powders, some of the new hydrides described as (UH 3 ) (1− x ) T x (T=Zr or Mo) remain monolithic, which allows to study transport and thermodynamic properties. [ABSTRACT FROM AUTHOR]

Magnetization and neutron diffraction measurements have been carried out to study evolution of structure and magnetic states of amorphous Nd 2 Fe 14 B and Er 2 Fe 14 B alloys under isothermal annealing at 295–1025 K. The amorphization have been performed by neutron irradiation which provides a homogeneous state in different with other methods of amorphization. The annealing induces a rise of α-Fe phase content in alloys and a recrystallization into Nd 2 Fe 14 B-type phase. Neutron diffraction data show that the recrystallization occurs over narrow temperature interval (590–638) K in Er 2 Fe 14 B and at around 800 K in Nd 2 Fe 14 B. Magnetic measurements testify that in both samples the magnetization and coercive field increase with annealing temperature above 800 K. [ABSTRACT FROM AUTHOR]

Highlights: [•] Magnetic phase diagrams of Nd2RhIn8 and Tb2RhIn8 were determined by magnetization measurements. [•] Both compounds order antiferromagnetically with the c-axis as the easy magnetization axis. [•] Their magnetic phase diagrams are qualitatively rather similar. [•] Additional magnetic phase which is formed when applying magnetic field along the c-axis. [ABSTRACT FROM AUTHOR]

Highlights: [•] Structure and magnetic states of alloys R2Fe14B (R=Nd, Er) before and after irradiation by fast neutrons with fluence up to 1.2×1020 neutrons per cm2 are studied. [•] The irradiation leads to amorphization of both alloys. [•] The Curie temperature considerably decreases and the coercivity vanishes upon irradiation of the samples. [•] Antiparallel orientation of the Fe and Er magnetic moments remains after amorphization in Er2Fe14B. [ABSTRACT FROM AUTHOR]

Abstract: Magnetic, thermal, and transport properties of a U3Fe4Ge4 single crystal have been studied. The compound crystallizes in the orthorhombic Gd3Cu4Ge4 structure type. U3Fe4Ge4 displays ferromagnetic order below the Curie temperature T C =18K. The magnetism originates from the uranium sublattice, as iron atoms have no ordered magnetic moments. U3Fe4Ge4 exhibits a pronounced easy-axis anisotropy with the anisotropy field exceeding 60T. The spontaneous magnetic moment is M s =1.2μB/f.u. at T =2K. Magnetic contribution to specific heat shows a gap excitation behavior with Δ =4meV, which can be related to the magnon gap due to the anisotropy. The Sommerfeld coefficient of the electronic specific heat is γ =57mJ/(mol-UK2) in the ordered state, whereas it is much higher (145mJ/(mol-UK2) if derived from the paramagnetic state. Electrical resistivity has very high values on the mΩcm range. [Copyright &y& Elsevier]

Abstract: Studies of magnetic and magneto-acoustic characteristics of the intermetallic compound UCu0.95Ge with antiferromagnetic ground state have been performed on single crystals in pulsed magnetic fields up to 64T applied along the main axes. Along the a axis, a first-order phase transition has been observed at 61T. For the field applied along the c axis, the first-order phase transition occurs at a much lower magnetic field (38T). In both directions, the magnetization trends to saturate at 1.35μB per formula unit. These field-induced transitions as well as the spontaneous transition at the magnetic ordering at T N =48K are accompanied by pronounced anomalies in the sound velocity and sound attenuation. The field-temperature phase diagrams are constructed for both directions of the magnetic field. The results of our theoretical analysis within the framework of the mean-field approximation qualitatively agree with the observed behavior of magnetic and magneto-acoustic characteristics of UCu0.95Ge. [Copyright &y& Elsevier]

Abstract: Hydrogenation of UTGe compounds results in formation of stable α- and β-hydrides, and modification of the crystal structure and magnetic properties. T C (3K) of UCoGe increases up to 50K in β-hydrides and T C (9.5K) of URhGe up to 17K in α-hydrides. The type of magnetic order is changed in UNiGe-H and UIrGe-H. The observed effects are attributed to the increased U–U spacing in the hydrides. [Copyright &y& Elsevier]

Abstract: U-based intermetallic compound UNiGe absorbs hydrogen up to the stoichiometry UNiGeH1.2. In analogy to other compounds with the TiNiSi-type of structure, the structure is modified into hexagonal. The zig-zag U-chains are stretched, the U–U spacing is largely enhanced and the ordering temperature increases up to 100K. The ordered state has a spontaneous moment, but it is unlikely to be a simple ferromagnet. [Copyright &y& Elsevier]

Abstract: Compounds R2−x Fe14+2x Si3 with (R=Ce, Nd, Gd, Dy, Ho, Er, Lu, Y) were prepared by the modified Czochralski method and investigated by means of the 57Fe 14.4keV Mössbauer spectroscopy and powder X-ray diffraction. The magnetic moment was additionally measured for samples being single crystals. Iron experiencing low magnetic hyperfine field and electric quadrupole interaction was found on (4e) sites in the P63/mmc structure. Similar iron was found in the structure as well. The non-stoichiometry parameter was determined as being close to 2x =0.5 for all compounds investigated. Compound with R=Ho crystallizes in both structures. Our results show that silicon avoids (4f) and (6g) sites for compounds with the P63/mmc structure (R=Dy, Ho, Er, Lu, Y), whereas it avoids (6c) and (9d) sites for those with structure (R=Nd, Gd, Ho). [Copyright &y& Elsevier]

Abstract: We studied crystal structure and magnetic properties of UCoSnH1.4 and URuSnH1.4 hydrides. They adopt the same hexagonal structure as the parent compounds. Both compounds remain ferromagnets after hydrogenation, but the tendencies of the magnetic properties differ: UCoSn exhibits a more typical behaviour expected for intermetallics of uranium upon hydrogenation ( increases from 82 to 102.5 K, the spontaneous magnetic moment increases from 0.64 to 0.70 /f.u.), but the influence of hydrogen absorption on URuSn is surprisingly opposite ( decreases from 54 to 51 K, its magnetic moment gets reduced to 0.48 /f.u. in URuSnH1.4 from 0.53 /f.u. in URuSn). [Copyright &y& Elsevier]

Abstract: The influence of pressure on the formation of U magnetic moments and mediation of exchange interactions are two principal aspects of the complex role of the 5f-ligand hybridization in magnetism of U intermetallics. Application of external pressure yields changes of interatomic distances, which are the crucial parameters controlling the hybridization. We report on pressure experiments with a 5f-electron ferromagnet UPtAl (T C=42.5K, M s=1.4 μ B/f.u. at ambient pressure). Application of hydrostatic pressure up to 1GPa yields decrease of the spontaneous magnetization M s with a rate dM s/dp=−0.027 μ B/GPa, whereas T C increases (dT C/dp=2.5K/GPa). Extension of the electrical resistivity measurements of UPtAl to pressures up to 22GPa reveals that the initial increase of T C with pressure continues up to 6GPa, where T C reaches the maximum value, and decreases with further increasing pressure. The drastic change of the R(T) curve at 17GPa is presumably connected with suppression of ferromagnetism in UPtAl. [Copyright &y& Elsevier]

The crystal structure and magnetic properties of the hydride UCoSiH0.7 and products of its thermal decomposition were studied. The hydrogenation of UCoSi leads to the modification of the crystal structure: the symmetry increases from orthorhombic (TiNiSi structure type) to hexagonal (ZrBeSi structure type) for UCoSiH0.7. UCoSi is a weak paramagnet. The hydrogenation enhances magnetic susceptibility, but does not yield magnetic ordering. The tendency observed for Curie–Weiss (CW) parameters, i.e. the shift of θP to less negative values and slight increase of effective moments, can be understood as due to a reduction of the characteristic energy of spin fluctuations. [Copyright &y& Elsevier]

We present the temperature and magnetic-field dependencies of the c-axis magnetization of a UCoAl single crystal under various uniaxial pressures exerted along the c-axis. The main result obtained is the uniaxial-pressure-induced reduction of the critical field of the metamagnetic transition followed by the formation of ferromagnetism at higher uniaxial-pressures. These and other associated results are discussed in comparison with corresponding data obtained by applying hydrostatic pressure on the same material. A scenario considering a variation of the anisotropic 5f-ligand hybridization and its consequences induced by the two different types of applied pressure is an important base for the discussion. The pressure-induced variations of the 5f–3d hybridization within the basal plane of the ZrNiAl-type hexagonal structure seem to be the underlying aspect of the evolution of the magnetism in UCoAl. [Copyright &y& Elsevier]

We discuss anomalies in temperature dependences of the electrical resistivity ρ(T) and thermal-expansion ΔL/L(T) observed for UTX compounds (T=transition metal, X=p-electron element) in paramagnetic range. We shall concentrate on the antiferromagnets UNiAl and UNiGa and the itinerant 5f-electron metamagnet UCoAl. The ρ(T) and ΔL/L(T) anomalies are usually strongly anisotropic and survive far above the Ne´el temperature or a characteristic temperature T* (UCoAl) but can be removed in a high magnetic field applied along the easy-magnetization direction (c-axis). In some cases, the available specific-heat data allow to calculate the entropy change ΔS connected with applying a high magnetic field along the c-axis. The ΔS values also show a maximum above TN (UNiAl, UNiGa) or T* (UCoAl) and then slowly decay with increasing temperatures. A possible scenario for these phenomena presented here, is based on existence of antiferromagnetic (AF) correlations and/or short-range AF ordering surviving in paramagnetic range. [Copyright &y& Elsevier]

The local magnetic moment configurations in the UCuxGe (x=0.90, 0.95 and 0.98) and UCuGey (y=0.90 and 0.95) non-stoichiometric intermetallic compounds were studied by means of Mo¨ssbauer spectroscopy in the temperature range 10–100 K. The 119Sn nuclei in Sn atoms doped on the Ge sites were exploited as a local probe. The vacancies on the Ge sites in UCuGey seem to have no considerable influence on the original magnetic structure of UCuGe. On the other hand, two ‘new’ magnetic moment configurations, which coexist at low temperatures with the original UCuGe magnetic structure, were observed in the Cu-deficient UCuxGe compounds. The changes of the mutual orientation of the U magnetic moments in the ‘new’ (perturbed) magnetic structure is due to the vacancy-induced variations of the effective exchange fields, which determines also the temperature evolution of magnetization. The observed anomalous temperature dependence of the hyperfine magnetic field on the 119Sn nuclei is qualitatively interpreted within the model of ‘melting’ of frustrated spins. [Copyright &y& Elsevier]

The evolution of the magnetic ordering temperature TM and the low-temperature magnetic structure in the quasibinary compounds U(Ge1−xSnx)2 for 0.01≤x≤1 were studied by means of 119Sn Mo¨ssbauer spectroscopy. These compounds are solid solutions between the ferromagnet UGe2 (TC=52 K) and the antiferromagnet USn2 (TN=75 K), both being collinear. The boundary compounds possess different easy-magnetization directions, the a- and c-axis, respectively. The minimum ordering temperature (Tmin≈36 K) has been found for x=0.58. The complex Mo¨ssbauer spectra observed for lower Sn concentrations could be attributed to the appearance of two non-collinear spin configurations characterized by a canting angle between pairs of U magnetic moments of 60 and 120°, respectively. When increasing the Sn concentration beyond x=0.58, the Mo¨ssbauer spectrum resembles that observed for USn2 which is accompanied by a rapid increase of TM. [Copyright &y& Elsevier]

• High anisotropy of saturation magnetization was observed in RCo 3 (R = Lu, Y) single crystals. • Belov-Arrott plots yield different T C along different crystallographic axis. • Anisotropy constants K 1 and K 2 vs. T were determined considering the magnetization anisotropy. We report on magnetization measurements of LuCo 3 and YCo 3 single crystals. These compounds show an instability of the 3 d -subsystem, whereby the Co atoms go from a low-spin to a high-spin state in applied magnetic field. In the low-spin state, we find a pronounced anisotropy of the saturation magnetization for LuCo 3 and YCo 3 , which can potentially lead to a large error in the determination of the anisotropy constant, K 2 , whereas the constant, K 1 , is much less affected. We also show that Belov-Arrott plots yield different values of the Curie temperature than obtained by magnetization curves along different crystallographic directions. [ABSTRACT FROM AUTHOR]

The effects of substitutional and interstitial atoms on the magnetic and magnetocaloric properties are investigated for R Ni (R is rare earth) compounds attractive for magnetic solid-state cooling at cryogenic temperatures. We focused on combining weakly and highly anisotropic rare earth compounds and obtained Gd x Dy 1-x Ni (x = 0.1 and 0.9) compounds and their Gd x Dy 1-x NiH 3 hydrides. We observed a considerable decrease in Curie temperatures (T C) in the hydrides Gd x Dy 1-x NiH 3 compared to their parent alloys. The magnetocaloric effect (MCE) values of Gd x Dy 1- x NiH y (y = 0 and 3) in the vicinity of T C were obtained and compared with literature data for the final GdNi and DyNi compounds. The maximum specific isothermal entropy changes -Δs T at μ 0 ΔH = 5 T were 14.5, 17, and 17.5 J kg−1K−1 for GdNi, Gd 0.9 Dy 0.1 Ni, and Gd 0.9 Dy 0.1 NiH 3 , respectively. For DyNi, Gd 0.1 Dy 0.9 Ni, and Gd 0.1 Dy 0.9 NiH 3 , they were -Δs T = 18, 15.5, and 12.5 J kg−1K−1 at μ 0 ΔH = 5 T, respectively. -Δs T (H) in Gd 0.9 Dy 0.1 NiH 3 at T = T C linearly increased in fields up to 7 T, while Gd 0.1 Dy 0.9 NiH 3 at T ≥ T C showed a plateau-like magnetocaloric effect at μ 0 ΔH = 5 and 7 T. The observed effects were explained based on altered exchange and magnetocrystalline interactions in the modified compounds. • New (GdDy)NiH 3 hydrides were obtained. • In Dy-rich compounds, the hydrogenation leads to a change of a crystal structure. • Hydrogenation leads to an extremely large reduction of the Curie temperature. • The (GdDy)NiH3 hydrides obey high values of the plateau-like magnetocaloric effect. [ABSTRACT FROM AUTHOR]

Abstract: The helimagnetic ground state was induced in the hexagonal Y2Fe17 and Lu2Fe17 intermetallics by hydrostatic pressure above 1.05 and 0.3GPa, respectively. The observed incommensurate helical structure was characterized by a propagation vector (00 τz ) and by a metamagnetic transition at the critical field H c. The new incommensurate magnetic structure has been revealed now in Lu2Fe17 at magnetic fields above H c at low temperatures. A detailed pressure-temperature-field evolution of the magnetic structures in Y2Fe17 and Lu2Fe17 is presented. [Copyright &y& Elsevier]

The crystal-electric field and exchange parameters are determined for the (Nd 0.5 Dy 0.5) 2 Fe 14 B compound by analyzing experimental magnetization curves obtained in high magnetic fields up to 58 T. The series (Nd x Dy 1-x) 2 Fe 14 B compounds were analyzed theoretically to achieve a temperature stability while maintaining a large maximum energy product (BH) max. We demonstrate that computational simulations is an important tool in the materials design. • The crystal-field and exchange parameters are determined. • The dependency of (BH)max on temperature was obtained. [ABSTRACT FROM AUTHOR]

Abstract: U2Co2Sn (Mo2FeB2 structure type, space group P4/mbm), exhibing non-Fermi liquid features and ferromagnetic spin fluctuations, is the first representative of the U2T2X series found to absorb hydrogen. Two hydrides are formed with different hydrogen content. The crystal structure type is not changed upon hydrogenation and the unit cell volume expands by 1.4% for -U2Co2SnH x and 8.1% for -U2Co2SnH y . Hydrogenation leads to magnetic ordering in both hydrides. -Hydride shows weak ferromagnetism below , whereas the -hydride is an antiferromagnet () similar to the other magnetically ordered hydrogen-free U2T2X compounds. [Copyright &y& Elsevier]

Fundamental characteristics of rare-earth (R) – iron intermetallics R 2 Fe 14 B are highly sensitive to the atomic substitutions and interstitial absorption of light elements. We studied a combined influence of the substitutions in the rare-earth sublattice and hydrogen absorption on the magnetization behavior in magnetic fields up to 60 T Er 2 Fe 14 B and Tm 2 Fe 14 B ferrimagnets chosen for the study showed that the substitution of Nd for Er or Tm increases the saturation magnetization as a result of ferromagnetic ordering of Nd and Fe moments. Under sufficiently high magnetic fields the magnetic moments rotate and the field-induced ferromagnetic state may be observed. The field at which a transition occurs is related to the strength of the inter-sublattice exchange interaction. The role of hydrogen is primarily to weaken the inter-sublattice ferrimagnetic coupling so that the reorientation becomes achievable at the available magnetic field strength (in hydrides Tm 2 Fe 14 BH 5.5 and (Tm 0.5 Nd 0.5) 2 Fe 14 BH 5.5). We analyze the volume dependence of the R–Fe magnetic interaction in R 2 Fe 14 B and compare it with other R –Fe compounds. • Characteristics of rare-earth–iron alloys are sensitive to both substitutions and interstitial absorption of light elements. • We studied a combined influence of the substitutions and hydrogen absorption on the magnetization behavior of R 2 Fe 14 B alloys. • We analyzed the volume dependence of magnetic interaction in R 2 Fe 14 B and compare it with other R–Fe compounds. [ABSTRACT FROM AUTHOR]

Abstract: The 5f-band system UCoAl, which crystallizes in the hexagonal ZrNiAl-type structure, has the paramagnetic ground state. The magnetic fields H as low as 0.6T oriented along the c-axis induce the metamagnetic transition below 17K. In order to study the magnetic property of UCoAl, we performed 27Al and 59Co NMR/NQR measurements in UCoAl, UCo0.98Fe0.02Al and UCo0.95Ni0.05Al single crystals. The substitution of Fe stabilizes the ferromagnetic state, and that of Ni stabilizes the paramagnetic state. The nuclear spin-lattice relaxation rate obtained with the crystal c-axis perpendicular to H is nearly six times larger than the with the c-axis parallel to H, which reflects the anisotropy of the spin fluctuations of the system. [Copyright &y& Elsevier]

Abstract: We have grown a CeCoGe single crystal and studied the specific heat as a function of temperature and magnetic field. At low temperatures also AC susceptibility and magnetization isotherms were measured. Clear attributes of the antiferromagnetic ordering below have been observed. The low-temperature specific heat (and the magnetic entropy) were considered when formulating a scenario of magnetic ordering in CeCoGe. [Copyright &y& Elsevier]

RE 2 Pd 2 In, RE 2 Pd 2 Sn compounds (RE = rare earth) absorb, depending on the rare earth (RE) element, different amounts of hydrogen. The parent compounds RE 2 Pd 2 In show the linear decrease of both lattice parameters and the unit cell volume with the increasing atomic number of RE, attributed to the lanthanide contraction. All the compounds absorb at least 2 H/f.u.; the tetragonal structure is merely expanded. The expansion is anisotropic (Δ c / c > Δ a / a ), and for RE = Tb, Dy, Ho, and Er the lattice even contracts along the a -axis (Δ a / a < 0), whereas Δ c / c still weakly increases. A higher H concentration can be achieved in the compounds with light rare earths (La, Nd, both for In and Sn), which then become amorphous. The magnetic ordering temperatures of all studied RE 2 Pd 2 In compounds are dramatically reduced by the hydrogenation, typically to the temperature range below 1.8 K. [ABSTRACT FROM AUTHOR]

Abstract: Effect of hydrogen absorption on the magnetic ordering temperatures in Lu2Fe17− x Si x (0⩽x⩽2) has been investigated. The antiferromagnetic state presented in Lu2Fe17 compound is suppressed and ferromagnetic state is stabilized by the substitution of Si for Fe. A considerable increase of Curie temperature () is observed for both cases: the substitution of Si for Fe and incorporation of hydrogen in the crystal lattice interstices. A relationship between the magnetic properties and unit cell volume in the Lu2Fe17− x Si x H y intermetallic compounds has been analyzed. [Copyright &y& Elsevier]