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Title: Crystal, magnetic, calorimetric and electronic structure investigation of GdScGe 1–xSb x compounds

Abstract

Here, experimental investigations of crystal structure, magnetism and heat capacity of compounds in the pseudoternary GdScGe-GdScSb system combined with density functional theory projections have been employed to clarify the interplay between the crystal structure and magnetism in this series of RTX materials (R = rare-earth, $ T$ = transition metal and X = p-block element). We demonstrate that the CeScSi-type structure adopted by GdScGe and CeFeSi-type structure adopted by GdScSb coexist over a limited range of compositions $$0.65 \leqslant x \leqslant 0.9$$ . Antimony for Ge substitutions in GdScGe result in an anisotropic expansion of the unit cell of the parent that is most pronounced along the c axis. We believe that such expansion acts as the driving force for the instability of the double layer CeScSi-type structure of the parent germanide. Extensive, yet limited Sb substitutions $$0 \leqslant x < 0.65$$ lead to a strong reduction of the Curie temperature compared to the GdScGe parent, but without affecting the saturation magnetization. With a further increase in Sb content, the first compositions showing the presence of the CeFeSi-type structure of the antimonide, $$x \approx 0.7$$ , coincide with the appearance of an antiferromagnetic phase. The application of a finite magnetic field reveals a jump in magnetization toward a fully saturated ferromagnetic state. This antiferro–ferromagnetic transformation is not associated with a sizeable latent heat, as confirmed by heat capacity measurements. The electronic structure calculations for $x = 0.75$ indicate that the key factor in the conversion from the ferromagnetic CeScSi-type to the antiferromagnetic CeFeSi-type structure is the disappearance of the induced magnetic moments on Sc. For the parent antimonide, heat capacity measurements indicate an additional transition below the main antiferromagnetic transition.

Authors:
ORCiD logo [1];  [1];  [1];  [1];  [1]; ORCiD logo [1]
  1. Ames Lab. and Iowa State Univ., Ames, IA (United States)
Publication Date:
Research Org.:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1411177
Report Number(s):
IS-J-9503
Journal ID: ISSN 0953-8984; TRN: US1800193
Grant/Contract Number:
AC02-07CH11358
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Journal of Physics. Condensed Matter
Additional Journal Information:
Journal Volume: 29; Journal Issue: 48; Journal ID: ISSN 0953-8984
Publisher:
IOP Publishing
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Guillou, F., Pathak, A. K., Hackett, T. A., Paudyal, D., Mudryk, Y., and Pecharsky, V. K.. Crystal, magnetic, calorimetric and electronic structure investigation of GdScGe1–xSbx compounds. United States: N. p., 2017. Web. doi:10.1088/1361-648X/aa93aa.
Guillou, F., Pathak, A. K., Hackett, T. A., Paudyal, D., Mudryk, Y., & Pecharsky, V. K.. Crystal, magnetic, calorimetric and electronic structure investigation of GdScGe1–xSbx compounds. United States. doi:10.1088/1361-648X/aa93aa.
Guillou, F., Pathak, A. K., Hackett, T. A., Paudyal, D., Mudryk, Y., and Pecharsky, V. K.. 2017. "Crystal, magnetic, calorimetric and electronic structure investigation of GdScGe1–xSbx compounds". United States. doi:10.1088/1361-648X/aa93aa.
@article{osti_1411177,
title = {Crystal, magnetic, calorimetric and electronic structure investigation of GdScGe1–xSbx compounds},
author = {Guillou, F. and Pathak, A. K. and Hackett, T. A. and Paudyal, D. and Mudryk, Y. and Pecharsky, V. K.},
abstractNote = {Here, experimental investigations of crystal structure, magnetism and heat capacity of compounds in the pseudoternary GdScGe-GdScSb system combined with density functional theory projections have been employed to clarify the interplay between the crystal structure and magnetism in this series of RTX materials (R = rare-earth, $ T$ = transition metal and X = p-block element). We demonstrate that the CeScSi-type structure adopted by GdScGe and CeFeSi-type structure adopted by GdScSb coexist over a limited range of compositions $0.65 \leqslant x \leqslant 0.9$ . Antimony for Ge substitutions in GdScGe result in an anisotropic expansion of the unit cell of the parent that is most pronounced along the c axis. We believe that such expansion acts as the driving force for the instability of the double layer CeScSi-type structure of the parent germanide. Extensive, yet limited Sb substitutions $0 \leqslant x < 0.65$ lead to a strong reduction of the Curie temperature compared to the GdScGe parent, but without affecting the saturation magnetization. With a further increase in Sb content, the first compositions showing the presence of the CeFeSi-type structure of the antimonide, $x \approx 0.7$ , coincide with the appearance of an antiferromagnetic phase. The application of a finite magnetic field reveals a jump in magnetization toward a fully saturated ferromagnetic state. This antiferro–ferromagnetic transformation is not associated with a sizeable latent heat, as confirmed by heat capacity measurements. The electronic structure calculations for $x = 0.75$ indicate that the key factor in the conversion from the ferromagnetic CeScSi-type to the antiferromagnetic CeFeSi-type structure is the disappearance of the induced magnetic moments on Sc. For the parent antimonide, heat capacity measurements indicate an additional transition below the main antiferromagnetic transition.},
doi = {10.1088/1361-648X/aa93aa},
journal = {Journal of Physics. Condensed Matter},
number = 48,
volume = 29,
place = {United States},
year = 2017,
month =
}

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