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All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Enrichment of the Galactic disc with neutron-capture elements: Gd, Dy, and Th

The study of the origin of heavy elements is one of the main goals of nuclear astrophysics. In this paper, we present new observational data for the heavy r-process elements gadolinium (Gd, Z= 64), dysprosium (Dy, Z= 66), and thorium (Th, Z= 90) in a sample of 276 Galactic disc stars (–1.0 < [Fe/H] < + 0.3). The stellar spectra have a high resolution of 42 000 and 75 000, and the signal-to-noise ratio higher than 100. The LTE abundances of Gd, Dy, and Th have been determined by comparing the observed and synthetic spectra for three Gd lines (149 stars), four Dy lines (152 stars), and the Th line at 4019.13 Å (170 stars). For about 70 percent of the stars in our sample, Gd and Dy are measured for the first time, and Th for 95 percent of the stars. Typical errors vary from 0.07 to 0.16 dex. This paper provides the first extended set of Th observations in the Milky Way disc. Here together with europium (Eu, Z= 63) data from our previous studies, we have compared these new observations with nucleosynthesis predictions and Galactic Chemical Evolution simulations. We confirm that [Gd/Fe] and [Dy/Fe] show the same behaviour of Eu. We study with GCE simulations the evolution of [Th/Fe] in comparison with [Eu/Fe], showing that unlike Eu, either the Th production is metallicity dependent in case of a unique source of the r-process in the Galaxy, or the frequency of the Th-rich r-process source is decreasing with the increase in [Fe/H].

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2020

Novel complex ceramic oxides, Ln 2 TiO 5 (Ln = La, Sm, Gd, Tb, Dy, Ho, Er, and Yb), for polyphase nuclear waste‐forms

Abstract As part of a broader study of ceramic nuclear waste‐forms, four different lanthanide titanates were fabricated; La 0.1 Sm 0.1 Gd 0.1 Tb 0.1 Dy 0.3 Ho 0.1 Er 0.2 YbTiO 5 , Sm 0.3 Gd 0.3 Dy 0.3 Yb 1.1 TiO 5 , Sm 0.1 Gd 0.4 Dy 0.4 Yb 1.1 TiO 5 , and Sm 0.2 Gd 0.2 Dy 0.2 Yb 1.4 TiO 5 . The aim was to produce single‐phase novel materials with cubic symmetry, capable of incorporating a wide variety of cations and with acceptable radiation tolerance. The chemistry flexibility and radiation tolerance are some of the major desirable properties for nuclear waste‐form materials. By using multiple lanthanides the average lanthanide radius can be controlled and consequently the structure, along with properties such as radiation tolerance. The radiation tolerance was assessed using in situ 1 MeV krypton irradiation and transmission electron microscopy characterization. Those materials for which cubic symmetry was achieved displayed better radiation tolerance; a greater critical fluence of ions ( F c ) was required for the crystalline to amorphous transition, and a lower temperature was required to maintain crystallinity ( T c ) during irradiation.

Aughterson, Robert D.↗
DOE OSTI2020

Materials Data on Dy(Ni2As)2 by Materials Project

DyNi4As2 crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. Dy is bonded to six equivalent As atoms to form a mixture of distorted edge and corner-sharing DyAs6 octahedra. The corner-sharing octahedral tilt angles are 40°. There are two shorter (2.89 Å) and four longer (2.92 Å) Dy–As bond lengths. Ni is bonded in a 3-coordinate geometry to three equivalent As atoms. There are two shorter (2.40 Å) and one longer (2.41 Å) Ni–As bond lengths. As is bonded in a 9-coordinate geometry to three equivalent Dy and six equivalent Ni atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Dy(MnGe)2 by Materials Project

DyMn2Ge2 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Dy is bonded in a 8-coordinate geometry to eight equivalent Ge atoms. All Dy–Ge bond lengths are 3.07 Å. Mn is bonded to four equivalent Ge atoms to form a mixture of edge and corner-sharing MnGe4 tetrahedra. All Mn–Ge bond lengths are 2.43 Å. Ge is bonded in a 9-coordinate geometry to four equivalent Dy, four equivalent Mn, and one Ge atom. The Ge–Ge bond length is 2.59 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Dy(IO3)3 by Materials Project

Dy(O3I)3 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of one Dy(O3I)3 sheet oriented in the (-1, 0, 2) direction. Dy3+ is bonded in a 7-coordinate geometry to eight O2- atoms. There are a spread of Dy–O bond distances ranging from 2.30–2.83 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Dy3+ and one I5+ atom. The O–I bond length is 1.85 Å. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two equivalent Dy3+ and one I5+ atom. The O–I bond length is 1.85 Å. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one Dy3+ and one I5+ atom. The O–I bond length is 1.84 Å. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Dy3+ and one I5+ atom. The O–I bond length is 1.84 Å. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to one I5+ atom. The O–I bond length is 1.87 Å. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Dy3+ and one I5+ atom. The O–I bond length is 1.84 Å. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one Dy3+ and one I5+ atom. The O–I bond length is 1.86 Å. In the eighth O2- site, O2- is bonded in a distorted single-bond geometry to one I5+ atom. The O–I bond length is 1.84 Å. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to one Dy3+ and one I5+ atom. The O–I bond length is 1.82 Å. There are three inequivalent I5+ sites. In the first I5+ site, I5+ is bonded in a 5-coordinate geometry to three O2- atoms. In the second I5+ site, I5+ is bonded in a 3-coordinate geometry to three O2- atoms. In the third I5+ site, I5+ is bonded in a 6-coordinate geometry to three O2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Dy(PPt4)2 by Materials Project

Dy(Pt4P)2 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of one Dy(Pt4P)2 sheet oriented in the (0, 0, 1) direction. Dy3+ is bonded to twelve Pt+0.62- atoms to form distorted face-sharing DyPt12 cuboctahedra. There are a spread of Dy–Pt bond distances ranging from 3.06–3.30 Å. There are four inequivalent Pt+0.62- sites. In the first Pt+0.62- site, Pt+0.62- is bonded in a 1-coordinate geometry to two equivalent Dy3+ and one P1+ atom. The Pt–P bond length is 2.23 Å. In the second Pt+0.62- site, Pt+0.62- is bonded in a distorted single-bond geometry to two equivalent Dy3+ and one P1+ atom. The Pt–P bond length is 2.29 Å. In the third Pt+0.62- site, Pt+0.62- is bonded in a distorted single-bond geometry to one Dy3+ and one P1+ atom. The Pt–P bond length is 2.33 Å. In the fourth Pt+0.62- site, Pt+0.62- is bonded in a distorted bent 120 degrees geometry to one Dy3+ and two equivalent P1+ atoms. Both Pt–P bond lengths are 2.36 Å. P1+ is bonded in a 5-coordinate geometry to five Pt+0.62- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Dy(BiO2)3 by Materials Project

Dy(BiO2)3 is Ilmenite-like structured and crystallizes in the trigonal R-3 space group. The structure is three-dimensional. there are two inequivalent Dy3+ sites. In the first Dy3+ site, Dy3+ is bonded in an octahedral geometry to six equivalent O2- atoms. All Dy–O bond lengths are 2.29 Å. In the second Dy3+ site, Dy3+ is bonded in an octahedral geometry to six equivalent O2- atoms. All Dy–O bond lengths are 2.28 Å. Bi3+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Bi–O bond distances ranging from 2.22–2.63 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to one Dy3+ and three equivalent Bi3+ atoms to form a mixture of distorted edge and corner-sharing ODyBi3 trigonal pyramids. In the second O2- site, O2- is bonded to one Dy3+ and three equivalent Bi3+ atoms to form a mixture of distorted edge and corner-sharing ODyBi3 trigonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Dy(PO3)3 by Materials Project

Dy(PO3)3 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent Dy3+ sites. In the first Dy3+ site, Dy3+ is bonded to six O2- atoms to form DyO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Dy–O bond distances ranging from 2.25–2.28 Å. In the second Dy3+ site, Dy3+ is bonded to six O2- atoms to form DyO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Dy–O bond distances ranging from 2.24–2.30 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two DyO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 25–29°. There are a spread of P–O bond distances ranging from 1.49–1.62 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent DyO6 octahedra and corners with two equivalent PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 11–39°. There is two shorter (1.50 Å) and two longer (1.61 Å) P–O bond length. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two DyO6 octahedra and corners with two PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 25–39°. There are a spread of P–O bond distances ranging from 1.50–1.62 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent DyO6 octahedra and corners with two equivalent PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 11–40°. There is two shorter (1.50 Å) and two longer (1.62 Å) P–O bond length. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Dy3+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Dy3+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted linear geometry to one Dy3+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the fifth O2- site, O2- is bonded in a linear geometry to one Dy3+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to one Dy3+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two P5+ atoms. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one Dy3+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to one Dy3+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two P5+ atoms. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Dy3+ and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Dy(BrO2)3 by Materials Project

Dy(O2Br)3 crystallizes in the monoclinic P2/c space group. The structure is two-dimensional and consists of one Dy(O2Br)3 sheet oriented in the (0, 1, 0) direction. Dy3+ is bonded in an octahedral geometry to six O2- atoms. There are a spread of Dy–O bond distances ranging from 2.22–2.30 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to one Dy3+ and one Br3+ atom. The O–Br bond length is 1.75 Å. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Dy3+ and one Br3+ atom. The O–Br bond length is 1.74 Å. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one Dy3+ and one Br3+ atom. The O–Br bond length is 1.77 Å. There are two inequivalent Br3+ sites. In the first Br3+ site, Br3+ is bonded in a water-like geometry to two equivalent O2- atoms. In the second Br3+ site, Br3+ is bonded in a water-like geometry to two O2- atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Dy(AsO)2 by Materials Project

Dy(AsO)2 is Cyanogen Chloride-like structured and crystallizes in the tetragonal I4_1/amd space group. The structure is zero-dimensional and consists of eight Dy(AsO)2 clusters. Dy3+ is bonded in a linear geometry to two equivalent O2- atoms. Both Dy–O bond lengths are 2.13 Å. As+0.50+ is bonded in a single-bond geometry to one O2- atom. The As–O bond length is 1.77 Å. O2- is bonded in a distorted linear geometry to one Dy3+ and one As+0.50+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Dy(NO3)3 by Materials Project

Dy(NO3)3 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of one Dy(NO3)3 sheet oriented in the (0, 0, 1) direction. Dy3+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Dy–O bond distances ranging from 2.37–2.73 Å. There are three inequivalent N5+ sites. In the first N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of N–O bond distances ranging from 1.25–1.28 Å. In the second N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.26 Å) and one longer (1.27 Å) N–O bond length. In the third N5+ site, N5+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of N–O bond distances ranging from 1.24–1.31 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Dy3+ and one N5+ atom. In the second O2- site, O2- is bonded in a distorted L-shaped geometry to one Dy3+ and one N5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Dy3+ and one N5+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to one Dy3+ and one N5+ atom. In the fifth O2- site, O2- is bonded in a distorted L-shaped geometry to one Dy3+ and one N5+ atom. In the sixth O2- site, O2- is bonded in a single-bond geometry to one Dy3+ and one N5+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to one Dy3+ and one N5+ atom. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to one Dy3+ and one N5+ atom. In the ninth O2- site, O2- is bonded in a distorted L-shaped geometry to one Dy3+ and one N5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Evolution of Physical Properties of RE 3 Ni 5 Al 19 Family (RE = Y, Nd, Sm, Gd, Tb, Dy, Ho, and Er)

In this study, single crystals of RE 3 Ni 5 Al 19 series (RE = Y, Nd, Sm, Gd, Tb, Dy, Ho, and Er) are grown using the Al self-flux method. The crystal structure is examined by both single crystal and powder X-ray diffraction. Physical properties are studied for the first time for RE 3 Ni 5 Al 19 (RE = Y, Nd, Gd, Tb, Dy, Ho, and Er) by means of magnetic susceptibility, electrical resistivity, and heat capacity measurements. Complex magnetic behaviors, with up to three transitions present for RE = Sm, Gd, Tb, and Dy, are revealed. Y 3 Ni 5 Al 19 is found to be a nonmagnetic nonsuperconducting metal (above T = 1.8 K) with weak electron–phonon coupling strength.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Quaternary i-MAX Phases (Mo 2/3 RE 1/3 ) 2 AlC (RE: Dy, Tb, Er): Experimental Characterization and First-Principles Insights into their Fundamental Properties

Rare earth (RE)-based materials have unique electronic, magnetic, and optical properties, leading to the recent discovery of atomically layered solids with the chemical formula (M' 2/3 RE 1/3 ) 2 AlC, which have since garnered significant attention in the scientific community. This study aims to synthesize, characterize, and investigate the structural and thermal stability of the RE i-MAX phases. We prepared i-MAX phases using molybdenum (Mo) as M′ and RE elements as Dy, Tb, and Er, namely (Mo 2/3 Dy 1/3 ) 2 AlC, (Mo 2/3 Tb 1/3 ) 2 AlC, and (Mo 2/3 Er 1/3 ) 2 AlC. Structural characterization through x-ray diffraction (XRD) and Raman spectroscopy confirms the formation of the RE-based i-MAX phase, along with the presence of minor impurity phases in the alloys. Thermogravimetric analysis (TGA) conducted up to 1000°C under ambient conditions reveals that the i-MAX phases remain thermally stable up to approximately 450°C, beyond which oxidation leads to a noticeable weight gain in all samples. Differential scanning calorimetry (DSC) measurements during heating and cooling cycles show endothermic and exothermic peaks for (Mo 2/3 Dy 1/3 ) 2 AlC i-MAX in the 410–420°C range, indicating a temperature-induced minor atomic arrangement. In contrast, these peaks are absent in the Tb- and Er-based i-MAX phases. These findings offer valuable insights into the thermal behavior and stability of these i-MAX phases under thermal stress, contributing to a deeper understanding of their unique properties. Furthermore, first-principles density functional theory (DFT) calculations were performed to investigate the electronic and optical properties of the i-MAX phases. The results reveal their metallic nature, with pronounced contributions from Mo and RE elements near the Fermi level and within the conduction band.

Rare earth↗
DOE OSTI2020

Magnetic and mechanical properties of grain-refined Dy-free Nd-Fe-B sintered magnets

In this work, the effects of grain size on magnetic and mechanical properties of Dy-free Nd-Fe-B sintered magnets were studied. The grain size of the sintered magnets was varied by using different sized Dy-free Nd-Fe-B alloy feedstock powders which were ball milled to different extents. Increasing the ball milling time from 7 to 11 h caused the average particle size of the powders to decrease from 3.6 to 2.1 µm, while the average grain size of the corresponding sintered magnets decreased from 5.0 to 4.0 µm. The intrinsic coercivity Hcj and maximum energy product (BH) max of these magnets increased from 11.6 to 13.7 kOe and 41.6 to 43.6 MGOe, respectively. The finer grain magnets exhibited better thermal stability, as indicated by a smaller temperature coefficient of H cj (-0.71%/°C). With extending ball milling time to 15 h, the magnetic properties of the magnets deteriorate, while the flexural strengths first decrease and then increase. The flexural strength improvement is attributed to the increased Oxygen content in the magnets due to finer grains. The coercivity enhancement by reduction of grain size is a promising approach to develop Dy-free Nd-Fe-B sintered magnets with better thermal stability. It is important to control the Oxygen contents in the magnets to compromise both magnetic and mechanical properties.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Competing Magnetic Interactions and the Role of Unpaired 4 f Electrons in Oxygen-Deficient Perovskites Ba 3 R Fe 2 O 7.5 ( R = Y, Dy)

Oxygen-deficient perovskite compounds with the general formula Ba 3 RFe 2 O 7.5 present a good opportunity to study competing magnetic interactions between Fe 3+ 3d cations with and without the involvement of unpaired 4f electrons on R 3+ cations. From analysis of neutron powder diffraction data, complemented by ab initio density functional theory calculations, we determined the magnetic ground states when R 3+ = Y 3+ (non-magnetic) and Dy 3+ (4f 9 ). They both adopt complex long-range ordered antiferromagnetic structures below T N = 6.6 and 14.5 K, respectively, with the same magnetic space group C a 2/c (BNS #15.91). However, the dominant influence of f-electron magnetism is clear in temperature dependence and differences between the size of the ordered moments on the two crystallographically independent Fe sites, one of which is enhanced by R–O–Fe superexchange in the Dy compound, while the other is frustrated by it. We report the Dy compound also shows evidence for temperature- and field-dependent transitions with hysteresis, indicating a field-induced ferromagnetic component below TN.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Molecular Dynamics and Free Energy Calculations of Dicyclohexano-18-crown-6 Diastereoisomers with Sm 2+ , Eu 2+ , Dy 2+ , Yb 2+ , Cf 2+ , and Three Halide Salts in Tetrahydrofuran and Acetonitrile Using the AMOEBA Force Field

With the continual development of lanthanides (Ln) in current technological devices, an efficient separation process is needed that can recover greater amounts of these rare elements. Dicyclohexano-18-crown-6(DCH18C6) is a crown ether that may be a promising candidate for Ln separation, but additional research is required. As such, molecular dynamics(MD) simulations have been performed on four divalent lanthanide halide salts(Sm 2+ , Eu 2+ , Dy 2+ , and Yb 2+ ) and one divalent actinide halide salt (Cf 2+ ) bound to three diastereoisomers of DCH18C6. Dy 2+ , Yb 2+ , Cf 2+ , DCH18C6, and tetrahydrofuran (THF) solvent were parameterized for the AMOEBA polarizable force field for the first time, whereas existing parameters for Sm 2+ and Eu 2+ were utilized from our previous efforts. A coordination number (CN) of six for Ln 2+ /An 2+ –O solvated in THF indicated that the cations interacted almost entirely with the oxygens of the polyether ring. A CN of one for Ln 2+ /An 2+ -N solvated in acetonitrile for systems containing iodide suggested that theN atom of acetonitrile was competitive with I – for cation interactions. Fluctuation between five and six CNs for Dy 2+ and Yb 2+ suggested that although the cations remained in the polyether ring, the size of the ring may not be an ideal fit as these cations possess comparatively smaller ionic radii. Gibbs binding free energies of Sm 2+ in all DCH18C6 diastereoisomers solvated in THF were calculated. The binding free energy of the cis-syn-cis diastereoisomer was the most favorable, followed by cis-anti-cis, and then trans-anti-trans. Lastly, two major types of conformation were observed for each diastereoisomer that were related to the electrostatic interactions and charge density of the cations.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Deconvolution of X-ray natural and magnetic circular dichroism in chiral Dy-ferroborate

Structural chirality and magnetism, when intertwined, can have profound implications on materials properties. Using X-ray imaging and spectroscopic measurements that leverage the natural and magnetic circular dichroic effects present in magnetized chiral crystal structures, we probe the interplay between chirality and magnetism across the field-induced spin-flop transition of Dy ferroborate, DyFe 3 (BO 3 ) 4 . Deconvolution of natural and magnetic circular dichroic signals at the Fe K and Dy L 2,3 absorption edges of the non-centrosymmetric structure was enabled by use of tunable temperature and magnetic field, providing access to element-specific magnetic information across the spin-flop transition. The magnetic response of Fe and Dy sublattices was found to be independent of domain chirality. The chiral domains were robust against both the (chirality preserving) R32 to P3 1 21/P3 2 21 structural phase transition at 280 K, and application of magnetic field up to 4 Tesla. A third flavor of X-ray dichroism, magneto-chiral dichroism, was not detected within the accuracy of our measurements. The absence of significant Fe magnetization along the screw, c-axis for the magnetic field strength used in this study, together with non-linear coupling of magnetic field to electric polarization across the spin-flop transition, may hinder observation of magneto-chiral dichroic effects in this system.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2022

Magnetic phase diagram of (Mo 2/3 RE 1/3 ) 2 AlC, RE = Tb and Dy, studied by magnetization, specific heat, and neutron diffraction analysis

We report the results of magnetization, heat capacity, and neutron diffraction measurements on (Mo 2/3 RE 1/3 ) 2 AlC with RE = Dy and Tb. Temperature and field-dependent magnetization as well as heat capacity were measured on a powder sample and on a single crystal allowing the construction of the magnetic field-temperature phase diagram. To study the magnetic structure of each magnetic phase, we applied neutron diffraction in a magnetic field up to 6 T. For (Mo 2/3 Dy 1/3 ) 2 AlC in zero field, a spin density wave is stabilized at 16 K, with antiferromagnetic ordering at 13 K. Furthermore, we identify the coexistence of ferromagnetic and antiferromagnetic phases induced by magnetic fields for both RE = Tb and Dy. The origin of the field induced phases is resulting from the competing ferromagnetic and antiferromagnetic interactions.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗