Anomalous specific heat and magnetic properties of TmxDy1-xAl2 (0 ≤ x ≤ 1)

Pathak, Arjun K.; Bonilla, C. M.; Paudyal, D.; Mudryk, Y.; Pecharsky, V. K.

doi:10.1016/j.jallcom.2018.09.365

Title: Anomalous specific heat and magnetic properties of Tm_xDy_1-xAl₂ (0 ≤ x ≤ 1)

Abstract

Here, we study crystal structure, phase transitions and magnetism of pseudo-binary Tm_xDy_1-xAl₂ (0 ≤ x ≤ 1) compounds using temperature dependent X-ray powder diffraction, specific heat and magnetization measurements, first principles, and model calculations. In low external magnetic fields, Dy-rich compounds undergo continuous, second-order phase transitions at the respective Curie temperatures, T_C. In contrast, the Tm-rich compounds exhibit discontinuous, first-order anomalies in the magnetically ordered states. These sharp transitions correlate with a substantial energy difference between the room temperature cubic and ground state rhombohedral structures of TmAl₂. A clear anomaly in the lattice parameter is observed at ~30 K for x = 0.5, which nearly coincides with T_C = 31.2 K. The effective quadrupolar moment of the lanthanides changes sign around x = 0.5, which leads to a nearly zero anisotropy constant and approximately spherical effective 4f charge densities, providing an explanation for the lack of structural distortions below T_C for x = 0.5. The calculations confirm [001] as the easy magnetization axis in the ground state tetragonal structure of DyAl₂, and reveal collapse of the orbital magnetic moment when the easy magnetization direction changes to [111]. Within the rhombohedral ground state of TmAl₂ [111] is the easy magnetization direction.

Authors:

^[1]; Bonilla, C. M. ^[1]; Paudyal, D. ^[1];

^[1];

^[1]

Ames Lab. and Iowa State Univ., Ames, IA (United States)

Publication Date:: Fri Sep 28 00:00:00 EDT 2018

Research Org.:: Ames Lab., Ames, IA (United States)

Sponsoring Org.:: USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:: 1478989

Alternate Identifier(s):: OSTI ID: 1642286

Report Number(s):: IS-J-9785
Journal ID: ISSN 0925-8388; PII: S0925838818336302

Grant/Contract Number:: AC02-07CH11358

Resource Type:: Accepted Manuscript

Journal Name:: Journal of Alloys and Compounds

Additional Journal Information:: Journal Volume: 774; Journal Issue: C; Journal ID: ISSN 0925-8388

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: 36 MATERIALS SCIENCE; Specific heat; Rare earth; First-order-phase-transition; Lanthanoids

Citation Formats


                    Pathak, Arjun K., Bonilla, C. M., Paudyal, D., Mudryk, Y., and Pecharsky, V. K. Anomalous specific heat and magnetic properties of TmxDy1-xAl2 (0 ≤ x ≤ 1).  United States: N. p., 2018. 
Web.  doi:10.1016/j.jallcom.2018.09.365.

Copy to clipboard


                    Pathak, Arjun K., Bonilla, C. M., Paudyal, D., Mudryk, Y., & Pecharsky, V. K. Anomalous specific heat and magnetic properties of TmxDy1-xAl2 (0 ≤ x ≤ 1).  United States.  https://doi.org/10.1016/j.jallcom.2018.09.365

Copy to clipboard


                    Pathak, Arjun K., Bonilla, C. M., Paudyal, D., Mudryk, Y., and Pecharsky, V. K. Fri .  
"Anomalous specific heat and magnetic properties of TmxDy1-xAl2 (0 ≤ x ≤ 1)".  United States.  https://doi.org/10.1016/j.jallcom.2018.09.365.  https://www.osti.gov/servlets/purl/1478989.

Copy to clipboard


                    
@article{osti_1478989,

  title        = {Anomalous specific heat and magnetic properties of TmxDy1-xAl2 (0 ≤ x ≤ 1)},

  author       = {Pathak, Arjun K. and Bonilla, C. M. and Paudyal, D. and Mudryk, Y. and Pecharsky, V. K.},

  abstractNote = {Here, we study crystal structure, phase transitions and magnetism of pseudo-binary TmxDy1-xAl2 (0 ≤ x ≤ 1) compounds using temperature dependent X-ray powder diffraction, specific heat and magnetization measurements, first principles, and model calculations. In low external magnetic fields, Dy-rich compounds undergo continuous, second-order phase transitions at the respective Curie temperatures, TC. In contrast, the Tm-rich compounds exhibit discontinuous, first-order anomalies in the magnetically ordered states. These sharp transitions correlate with a substantial energy difference between the room temperature cubic and ground state rhombohedral structures of TmAl2. A clear anomaly in the lattice parameter is observed at ~30 K for x = 0.5, which nearly coincides with TC = 31.2 K. The effective quadrupolar moment of the lanthanides changes sign around x = 0.5, which leads to a nearly zero anisotropy constant and approximately spherical effective 4f charge densities, providing an explanation for the lack of structural distortions below TC for x = 0.5. The calculations confirm [001] as the easy magnetization axis in the ground state tetragonal structure of DyAl2, and reveal collapse of the orbital magnetic moment when the easy magnetization direction changes to [111]. Within the rhombohedral ground state of TmAl2 [111] is the easy magnetization direction.},

  doi          = {10.1016/j.jallcom.2018.09.365},

  journal      = {Journal of Alloys and Compounds},

  number       = C,

  volume       = 774,

  place        = {United States},

  year         = {Fri Sep 28 00:00:00 EDT 2018},

  month        = {Fri Sep 28 00:00:00 EDT 2018}

}

Copy to clipboard

Journal Article:

Free Publicly Available Full Text

Accepted Manuscript (Publisher)

Accepted Manuscript (DOE)

Publisher's Version of Record

https://doi.org/10.1016/j.jallcom.2018.09.365

Other availability

Search WorldCat to find libraries that may hold this journal

Citation Metrics:

Cited by: 5 works

Citation information provided by
Web of Science

Figures / Tables:

TABLE I: Lattice constants and magnetic parameters obtained for Tm_xDy_1-xAl₂ compounds.

All figures and tables (14 total)

Save / Share:

Export Metadata

Save to My Library

Figures / Tables found in this record:

Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.

Similar Records in DOE PAGES and OSTI.GOV collections:

Anisotropy induced anomalies in Dy_1$$-$$xTb_xAl₂

Journal Article Khan, M. ; Miami Univ., Oxford, OH ; Pathak, A. K. ; ... - Journal of Materials Chemistry. C

The Dy_{1more » $$-$$x}Tb_xAl₂ alloys have been investigated by X-ray powder diffraction, heat capacity, and magnetic measurements. All samples exhibit cubic Laves phase crystal structure at room temperature but at T_C, DyAl2 and TbAl₂ show tetragonal and rhombohedral distortions, respectively. First order phase transitions are observed below T_C (at the spin-reorientation transition, T_SR) in the alloys with 0.15 ≤ x ≤ 0.35. These transitions are signified by sharp heat capacity peaks and corresponding anomalies in the magnetization and ac magnetic susceptibility data. The observations are interpreted by taking into consideration the differences in easy magnetization directions of DyAl₂ and TbAl₂. Due to the competing magnetic structures, the anisotropy-related instability and magnetic frustrations are prominent in the Dy_1$$-$$xTb_xAl₂ alloys at certain concentrations resulting in the first order transitions.« less
Cited by 7
https://doi.org/10.1039/C6TC05384J

Full Text Available
Anisotropic magnetization and transport properties of RAgSb₂ (R=Y, La-Nd, Sm, Gd-Tm)

Thesis/Dissertation Myers, Kenneth D.

This study of the RAgSb₂ series of compounds arose as part of an investigation of rare earth intermetallic compounds containing antimony with the rare earth in a position with tetragonal point symmetry. Materials with the rare earth in a position with tetragonal point symmetry frequently manifest strong anisotropies and rich complexity in the magnetic properties, and yet are simple enough to analyze. Antimony containing intermetallic compounds commonly possess low carrier densities and have only recently been the subject of study. Large single grain crystals were grown of the RAgSb₂ (R=Y, La-Nd, Sm, Gd-Tm) series of compounds out of a highmore »« less
https://doi.org/10.2172/754787

Full Text Available
Couples Magnetic and Structural Transitions in High-Purity Dy and Gd₅Sb_xGe_4-x

Thesis/Dissertation Chernyshov, Alexander S.

Magnetic materials exhibiting magnetic phase transitions simultaneously with structural rearrangements of their crystal lattices hold a promise for numerous applications including magnetic refrigeration, magnetomechanical devices and sensors. We undertook a detailed study of a single crystal of dysprosium metal, which is a classical example of a system where magnetic and crystallographic sublattices can be either coupled or decoupled from one another. Magnetocaloric effect, magnetization, ac magnetic susceptibility, and heat capacity of high purity single crystals of dysprosium have been investigated over broad temperature and magnetic field intervals with the magnetic field vector parallel to either the a- or c-axes ofmore »« less
https://doi.org/10.2172/892728

Full Text Available
Magnetic properties of the random-axis magnet (Dy sub x Y sub 1-x )Al sub 2

Miscellaneous Gehring, P M

The effects of a random component of the magnetocrystalline anisotropy on the magnetic properties and critical behavior of DyAl{sub 2} have been investigated using bulk magnetic measurements. Randomness in the magnetic anisotropy is brought about by site diluting ferromagnetic DyAl{sub 2} with the non-magnetic, isomorphic intermetallic YAl{sub 2}. Dilution causes a distortion of the cubic Laves phase unit cell because of the lattice mismatch between DyAl{sub 2} and YAl{sub 2}, and lowers the local crystal symmetry. This effect induces a random component of the magnetic anisotropy and causes the local easy axis of magnetization to vary in direction from sitemore »« less
Correlation between magnetostriction and magnetic structure in pseudobinary compounds Tb(Co_1-xFe_x)₂

Journal Article Wang, Yue ; Ma, Tianyu ; Wu, Chen ; ... - AIP Advances

Giant low-field magnetostriction has been achieved in pseudobinary Laves phase compounds RR’T₂ (R and R’: rare earth elements; T: transition metal elements) around the ferromagnetic - ferromagnetic (ferro.-ferro.) transition temperature. Evolution of the magnetic structure across such transition requires comprehensive investigation. In this work, pseudobinary system Tb(Co_1-xFe_x)₂ is selected to investigate the evolution of local magnetic moment, for which two end terminals TbCo₂ and TbFe₂ possess the rhombohedral (R) structure at the ferromagnetic state but with different magnetic ordering temperatures (T_C). Magnetometry measurements reveal that a composition independent ferromagnetic - ferromagnetic transition occurs at ~100 K despite the increased Curiemore »« less
Cited by 12
https://doi.org/10.1063/1.4991734

Full Text Available

Similar Records

Title: Anomalous specific heat and magnetic properties of TmxDy1-xAl2 (0 ≤ x ≤ 1)

Abstract

Citation Formats

Figures / Tables:

Title: Anomalous specific heat and magnetic properties of Tm_xDy_1-xAl₂ (0 ≤ x ≤ 1)