Competition of L21 and L10 ordering in Pd2MnSe, Pd2FeSe, Pd2MnTe and Pd2FeTe Heusler alloys
Based on first-principles method, for Pd2MnSe, Pd2FeSe, Pd2MnTe and Pd2FeTe, we investigated the competition between cubic L21-type and their tetragonal L10-type ordering. Firstly, low-energy tetragonal ground states are found in these alloys during the tetragonal deformation. By regulating the c/a...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2019-03-01
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| Series: | Results in Physics |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2211379718331851 |
| _version_ | 1811234999445225472 |
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| author | Mengxin Wu Yilin Han Liying Wang Tie Yang Minquan Kuang Xuebin Chen Xiaotian Wang |
| author_facet | Mengxin Wu Yilin Han Liying Wang Tie Yang Minquan Kuang Xuebin Chen Xiaotian Wang |
| author_sort | Mengxin Wu |
| collection | DOAJ |
| description | Based on first-principles method, for Pd2MnSe, Pd2FeSe, Pd2MnTe and Pd2FeTe, we investigated the competition between cubic L21-type and their tetragonal L10-type ordering. Firstly, low-energy tetragonal ground states are found in these alloys during the tetragonal deformation. By regulating the c/a ratio under the fixed volume of equilibrium cubic phase, we obtain two minimums in total energy-c/a curve: a shallow one in c/a < 1 and the deeper one in c/a > 1. Meanwhile the uniform strain is also taken into consideration in this work, and we found that ΔEM and Vopt + X%Vopt are negatively correlated, that is, with the volume increases from Vopt − 3%Vopt to Vopt + 3%Vopt, the absolute value of ΔEM decreases accordingly. Secondly, the origin of the tetragonal ground states of Pd2 [Fe/Mn][Se/Te] are also be explained by the density of states (DOS) figures. From the valley-and-peak structure, we can find the DOS at or in the vicinity of the Fermi level is much broader and shallower in tetragonal L10 state than cubic L21 state, indicating the phase stability of tetragonal L10 phases of these Pd2-based alloys. Moreover, to further study the competition of L21 and L10 ordering in these alloys and verify the stability of the tetragonal L10 state, elastic constants were introduced in this work, C11, C12 and C44 for cubic state while C11, C12, C13, C33, C44, C66 for tetragonal L10-type structure. According to the judgment basis, all alloys exhibit L10-stable, satisfying our conclusions about the stability of tetragonal states. We hope our work can provide a guidance for researchers to further explore and study new magnetic functional tetragonal materials among the full-Heusler alloys. Keywords: L21 and L10 ordering, Tetragonal ground state, Elastic constant |
| first_indexed | 2024-04-12T11:43:48Z |
| format | Article |
| id | doaj.art-3c83f539b7884ab6992565777ef42ce0 |
| institution | Directory Open Access Journal |
| issn | 2211-3797 |
| language | English |
| last_indexed | 2024-04-12T11:43:48Z |
| publishDate | 2019-03-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Results in Physics |
| spelling | doaj.art-3c83f539b7884ab6992565777ef42ce02022-12-22T03:34:26ZengElsevierResults in Physics2211-37972019-03-011213981404Competition of L21 and L10 ordering in Pd2MnSe, Pd2FeSe, Pd2MnTe and Pd2FeTe Heusler alloysMengxin Wu0Yilin Han1Liying Wang2Tie Yang3Minquan Kuang4Xuebin Chen5Xiaotian Wang6School of Physical Science and Technology, Southwest University, Chongqing 400715, PR ChinaSchool of Physical Science and Technology, Southwest University, Chongqing 400715, PR ChinaTianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, Faculty of Science, Tianjin University, Tianjin 300350, PR ChinaSchool of Physical Science and Technology, Southwest University, Chongqing 400715, PR ChinaSchool of Physical Science and Technology, Southwest University, Chongqing 400715, PR ChinaHebei Key Laboratory of Data Science and Application, North China University of Science and Technology, Tangshan 063009, PR China; Tangshan Key Laboratory of Data Science, North China University of Science and Technology, Tangshan 063009, PR ChinaSchool of Physical Science and Technology, Southwest University, Chongqing 400715, PR China; Hebei Key Laboratory of Data Science and Application, North China University of Science and Technology, Tangshan 063009, PR China; Tangshan Key Laboratory of Data Science, North China University of Science and Technology, Tangshan 063009, PR China; Corresponding author at: School of Physical Science and Technology, Southwest University, Chongqing 400715, PR China.Based on first-principles method, for Pd2MnSe, Pd2FeSe, Pd2MnTe and Pd2FeTe, we investigated the competition between cubic L21-type and their tetragonal L10-type ordering. Firstly, low-energy tetragonal ground states are found in these alloys during the tetragonal deformation. By regulating the c/a ratio under the fixed volume of equilibrium cubic phase, we obtain two minimums in total energy-c/a curve: a shallow one in c/a < 1 and the deeper one in c/a > 1. Meanwhile the uniform strain is also taken into consideration in this work, and we found that ΔEM and Vopt + X%Vopt are negatively correlated, that is, with the volume increases from Vopt − 3%Vopt to Vopt + 3%Vopt, the absolute value of ΔEM decreases accordingly. Secondly, the origin of the tetragonal ground states of Pd2 [Fe/Mn][Se/Te] are also be explained by the density of states (DOS) figures. From the valley-and-peak structure, we can find the DOS at or in the vicinity of the Fermi level is much broader and shallower in tetragonal L10 state than cubic L21 state, indicating the phase stability of tetragonal L10 phases of these Pd2-based alloys. Moreover, to further study the competition of L21 and L10 ordering in these alloys and verify the stability of the tetragonal L10 state, elastic constants were introduced in this work, C11, C12 and C44 for cubic state while C11, C12, C13, C33, C44, C66 for tetragonal L10-type structure. According to the judgment basis, all alloys exhibit L10-stable, satisfying our conclusions about the stability of tetragonal states. We hope our work can provide a guidance for researchers to further explore and study new magnetic functional tetragonal materials among the full-Heusler alloys. Keywords: L21 and L10 ordering, Tetragonal ground state, Elastic constanthttp://www.sciencedirect.com/science/article/pii/S2211379718331851 |
| spellingShingle | Mengxin Wu Yilin Han Liying Wang Tie Yang Minquan Kuang Xuebin Chen Xiaotian Wang Competition of L21 and L10 ordering in Pd2MnSe, Pd2FeSe, Pd2MnTe and Pd2FeTe Heusler alloys Results in Physics |
| title | Competition of L21 and L10 ordering in Pd2MnSe, Pd2FeSe, Pd2MnTe and Pd2FeTe Heusler alloys |
| title_full | Competition of L21 and L10 ordering in Pd2MnSe, Pd2FeSe, Pd2MnTe and Pd2FeTe Heusler alloys |
| title_fullStr | Competition of L21 and L10 ordering in Pd2MnSe, Pd2FeSe, Pd2MnTe and Pd2FeTe Heusler alloys |
| title_full_unstemmed | Competition of L21 and L10 ordering in Pd2MnSe, Pd2FeSe, Pd2MnTe and Pd2FeTe Heusler alloys |
| title_short | Competition of L21 and L10 ordering in Pd2MnSe, Pd2FeSe, Pd2MnTe and Pd2FeTe Heusler alloys |
| title_sort | competition of l21 and l10 ordering in pd2mnse pd2fese pd2mnte and pd2fete heusler alloys |
| url | http://www.sciencedirect.com/science/article/pii/S2211379718331851 |
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