Dariusz J. Gawryluk^1*, Y. Maximilian Klein^1*, Tian Shang^1*, Denis Sheptyakov^2*, Lukas Keller^2*, Nicola Casati^3*, Philippe Lacorre^4*, Maria Teresa Fernandez-Diaz^5*, Juan Rodriguez-Carvajal^5*, Marisa Medarde^1*

1 Laboratory for Multiscale Materials Experiments, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland

2 Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland

3 Swiss Light Source, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland

4 Institut des Molécules et Matériaux du Mans (IMMM) - UMR 6283 CNRS, Le Mans Université, Avenue Olivier Messiaen, 72085 Le Mans, France

5 Institut Laue Langevin, 71 avenue des Martyrs, CS 20156 -38042 Grenoble CEDEX 9, France

* Corresponding authors emails: dariusz.gawryluk@psi.ch, maximilian.klein@psi.ch, tian.shang@psi.ch, denis.cheptiakov@psi.ch, lukas.keller@psi.ch, nicola.casati@psi.ch, philippe.lacorre@univ-lemans.fr, ferndiaz@ill.fr, jrc@ill.dr, marisa.medarde@psi.ch

DOI10.24435/materialscloud:2019.0084/v2 [version v2]

Publication date: Dec 14, 2019

How to cite this record

Dariusz J. Gawryluk, Y. Maximilian Klein, Tian Shang, Denis Sheptyakov, Lukas Keller, Nicola Casati, Philippe Lacorre, Maria Teresa Fernandez-Diaz, Juan Rodriguez-Carvajal, Marisa Medarde, Distortion mode anomalies in bulk PrNiO3: Illustrating the potential of symmetry-adapted distortion mode analysis for the study of phase transitions, Materials Cloud Archive 2019.0084/v2 (2019), doi: 10.24435/materialscloud:2019.0084/v2.

Description

The origin of the metal-to-insulator transition (MIT) in RNiO3 perovskites with R = trivalent 4 f ion has challenged the condensed matter research community for almost three decades. A drawback for progress in this direction has been the lack of studies combining physical properties and accurate structural data covering the full nickelate phase diagram. Here we focus on a small region close to the itinerant limit (R = Pr, 1.5 K < T < 300 K), where we investigate the gap opening and the simultaneous emergence of charge order in PrNiO3. We combine electrical resistivity, magnetization, and heat capacity measurements with high-resolution neutron and synchrotron x-ray powder diffraction data that, in contrast to previous studies, we analyze in terms of symmetry-adapted distortion modes. Such analysis allow us to identify the contribution of the different modes to the global distortion in a broad temperature range. Moreover, it shows that the structural changes at the MIT, traditionally described in terms of the evolution of the interatomic distances and angles, appear as abrupt increases of all nonzero mode amplitudes at TMIT = TN ∼ 130 K accompanied by the appearance of new modes below this temperature. A further interesting observation is the existence of a nearly perfect linear correlation between the amplitude of the breathing mode associated to the charge order and the staggered magnetization below the MIT. Our data also uncover a previously unnoticed anomaly at T ∗ ∼ 60 K (∼0.4 × TMIT), clearly visible in the electrical resistivity, lattice parameters and some mode amplitudes. Since phase coexistence is only observed in a small temperature region around TMIT (∼±10 K), these observations suggest the existence of a hidden symmetry in the insulating phase. We discuss some possible origins, among them the theoretically predicted existence of polar distortions induced by the noncentrosymmetric magnetic order [Perez-Mato et al., J. Phys.: Condens. Matter 28, 286001 (2016); Giovanetti et al., Phys. Rev. Lett. 103, 156401 (2009)].

Materials Cloud sections using this data

Files

File name	Size	Description
Data_files.zip MD5md5:39d5839c6941fea386277dc33d48180c	35.4 MiB	Experimental data files (text or excel format).
Input+Output_Basireps_SG_221_SG_62.txt MD5md5:1f305701d0f551657895c8dbfbc06b6e	3.5 KiB	Amplimodes input (SG Pbnm), text format
Input+Output_Basireps_SG_221_SG_14.txt MD5md5:7333e3b0a6958949c1475a4faab071ce	4.9 KiB	Amplimodes input (SG P21/n), text format
FullProf_input_data_magn+amplimodes.docx MD5md5:f14a7010f54fe844fd483c7617b650d3	31.9 KiB	Detailed output (Amplimodes fits), docx format
FullProf_input_data_cryst_structure.txt MD5md5:15febe9f045c6d2e430eb14fb58de9db	40.8 KiB	Detailed output (Atomic coordinate fits), text format
Readme.txt MD5md5:cca68bb2a021c5b573a5d82e8be6ceed	681 Bytes	Contents of the folder "Data_files.zip" , text format

License

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Metadata, except for email addresses, are licensed under the Creative Commons Attribution Share-Alike 4.0 International license.

External references

Keywords

MARVEL/DD5 metal-insulator transition synchrotron x-ray diffraction physical properties distortion mode amplitudes neutron diffraction