Fine Structure of Metal–Insulator Transition in EuO Resolved by Doping Engineering | Sciact - CRIS-system of Boreskov Institute of Catalysis

Fine Structure of Metal–Insulator Transition in EuO Resolved by Doping Engineering Full article

Journal

Nanotechnology
ISSN: 0957-4484 , E-ISSN: 1361-6528

Output data

Year: 2018, Volume: 29, Number: 19, Article number : 195706, Pages count : 10 DOI: 10.1088/1361-6528/aab16e

Tags

metal-insulator transition, EuO, magnetic polaron, resistivity, XMCD

Authors

Averyanov Dmitry V ¹ , Parfenov Oleg E ¹ , Tokmachev Andrey M ¹ , Karateev Igor A ¹ , Kondratev Oleg A ¹ , Taldenkov Alexander N ¹ , Platunov Mikhail S ² , Wilhelm Fabrice ² , Rogalev Andrei ² , Storchak Vyacheslav G ¹

Affiliations

1	National Research Center ‘Kurchatov Institute’, Kurchatov Sq. 1, Moscow 123182, Russia
2	European Synchrotron Radiation Facility (ESRF), F-38054 Grenoble Cedex, France

Metal-insulator transitions (MITs) offer new functionalities for nanoelectronics. However, ongoing attempts to control the resistivity by external stimuli are hindered by strong coupling of spin, charge, orbital and lattice degrees of freedom. This difficulty presents a quest for materials which exhibit MIT caused by a single degree of freedom. In the archetypal ferromagnetic semiconductor EuO, magnetic orders dominate the MIT. Here we report a new approach to take doping under control in this material on the nanoscale: formation of oxygen vacancies is strongly suppressed to exhibit the highest MIT resistivity jump and magnetoresistance among thin films. The nature of the MIT is revealed in Gd doped films. The critical doping is determined to be more than an order of magnitude lower than in all previous studies. In lightly doped films, a remarkable thermal hysteresis in resistivity is discovered. It extends over 100 K in the paramagnetic phase reaching 3 orders of magnitude. In the warming mode, the MIT is shown to be a two-step process. The resistivity patterns are consistent with an active role of magnetic polarons-formation of a narrow band and its thermal destruction. High-temperature magnetic polaron effects include large negative magnetoresistance and ferromagnetic droplets revealed by x-ray magnetic circular dichroism. Our findings have wide-range implications for the understanding of strongly correlated oxides and establish fundamental benchmarks to guide theoretical models of the MIT.

Averyanov D.V. , Parfenov O.E. , Tokmachev A.M. , Karateev I.A. , Kondratev O.A. , Taldenkov A.N. , Platunov M.S. , Wilhelm F. , Rogalev A. , Storchak V.G.
Fine Structure of Metal–Insulator Transition in EuO Resolved by Doping Engineering
Nanotechnology. 2018. V.29. N19. 195706 :1-10. DOI: 10.1088/1361-6528/aab16e WOS Scopus РИНЦ ANCAN OpenAlex

Submitted:	Jan 9, 2018
Accepted:	Feb 22, 2018
Published print:	Mar 16, 2018
Published online:	Mar 16, 2018

Web of science:	WOS:000427651700002
Scopus:	2-s2.0-85044025917
Elibrary:	35495708
Chemical Abstracts:	2018:2233396
Chemical Abstracts (print):	176:175529
OpenAlex:	W2793591136

DB	Citing
Web of science	26
Scopus	25
OpenAlex	24