skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Vacancy-Driven Noncubic Local Structure and Magnetic Anisotropy Tailoring in Fe xO-Fe 3- δO 4 Nanocrystals

Abstract

In contrast to bulk materials, nanoscale crystal growth is critically influenced by size- and shape-dependent properties. However, it is challenging to decipher how stoichiometry, in the realm of mixed-valence elements, can act to control physical properties, especially when complex bonding is implicated by short and long-range ordering of structural defects. Here, solution-grown iron-oxide nanocrystals (NCs) of the pilot wüstite system are found to convert into iron-deficient rock-salt and ferro-spinel sub-domains, but attain a surprising tetragonally distorted local structure. Cationic vacancies within chemically uniform NCs are portrayed as the parameter to tweak the underlying properties. These lattice imperfections are shown to produce local exchange-anisotropy fields that reinforce the nanoparticles’ magnetization and overcome the influence of finite-size effects. The concept of atomic-scale defect control in subcritical size NCs, aspires to become a pathway to tailor-made properties with improved performance for hyperthermia heating over defect-free NCs.

Authors:
 [1]; ORCiD logo [2];  [3];  [1];  [4];  [4];  [5];  [5];  [1];  [6];  [6]
  1. Foundation for Research and Technology - Hellas, Heraklion (Greece)
  2. Brookhaven National Lab. (BNL), Upton, NY (United States); Univ. College, London (United Kingdom)
  3. Foundation for Research and Technology - Hellas, Heraklion (Greece); Univ. of Crete, Heraklion (Greece)
  4. National Center for Scientific Research Demokritos, Athens (Greece)
  5. Univ. of Naples Federico II, Naples (Italy)
  6. Brookhaven National Lab. (BNL), Upton, NY (United States)
Publication Date:
Research Org.:
Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1575957
Alternate Identifier(s):
OSTI ID: 1573471
Report Number(s):
BNL-212282-2019-JAAM
Journal ID: ISSN 2160--3308
Grant/Contract Number:  
SC0012704
Resource Type:
Published Article
Journal Name:
Physical Review X
Additional Journal Information:
Journal Volume: 9; Journal Issue: 4; Journal ID: ISSN 2160--3308
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Lapas, Alexandros, Robinson, Ian K., Antonaropoulos, George, Brintakis, Konstantinos, Vasilakaki, Marianna, Trohidou, Kalliopo N., Iannotti, Vincenzo, Ausanio, Giovanni, Kostopoulou, Athanasia, Abeykoon, Milinda, and Bozin, Emil S. Vacancy-Driven Noncubic Local Structure and Magnetic Anisotropy Tailoring in FexO-Fe3-δO4 Nanocrystals. United States: N. p., 2019. Web. doi:10.1103/PhysRevX.9.041044.
Lapas, Alexandros, Robinson, Ian K., Antonaropoulos, George, Brintakis, Konstantinos, Vasilakaki, Marianna, Trohidou, Kalliopo N., Iannotti, Vincenzo, Ausanio, Giovanni, Kostopoulou, Athanasia, Abeykoon, Milinda, & Bozin, Emil S. Vacancy-Driven Noncubic Local Structure and Magnetic Anisotropy Tailoring in FexO-Fe3-δO4 Nanocrystals. United States. doi:10.1103/PhysRevX.9.041044.
Lapas, Alexandros, Robinson, Ian K., Antonaropoulos, George, Brintakis, Konstantinos, Vasilakaki, Marianna, Trohidou, Kalliopo N., Iannotti, Vincenzo, Ausanio, Giovanni, Kostopoulou, Athanasia, Abeykoon, Milinda, and Bozin, Emil S. Fri . "Vacancy-Driven Noncubic Local Structure and Magnetic Anisotropy Tailoring in FexO-Fe3-δO4 Nanocrystals". United States. doi:10.1103/PhysRevX.9.041044.
@article{osti_1575957,
title = {Vacancy-Driven Noncubic Local Structure and Magnetic Anisotropy Tailoring in FexO-Fe3-δO4 Nanocrystals},
author = {Lapas, Alexandros and Robinson, Ian K. and Antonaropoulos, George and Brintakis, Konstantinos and Vasilakaki, Marianna and Trohidou, Kalliopo N. and Iannotti, Vincenzo and Ausanio, Giovanni and Kostopoulou, Athanasia and Abeykoon, Milinda and Bozin, Emil S.},
abstractNote = {In contrast to bulk materials, nanoscale crystal growth is critically influenced by size- and shape-dependent properties. However, it is challenging to decipher how stoichiometry, in the realm of mixed-valence elements, can act to control physical properties, especially when complex bonding is implicated by short and long-range ordering of structural defects. Here, solution-grown iron-oxide nanocrystals (NCs) of the pilot wüstite system are found to convert into iron-deficient rock-salt and ferro-spinel sub-domains, but attain a surprising tetragonally distorted local structure. Cationic vacancies within chemically uniform NCs are portrayed as the parameter to tweak the underlying properties. These lattice imperfections are shown to produce local exchange-anisotropy fields that reinforce the nanoparticles’ magnetization and overcome the influence of finite-size effects. The concept of atomic-scale defect control in subcritical size NCs, aspires to become a pathway to tailor-made properties with improved performance for hyperthermia heating over defect-free NCs.},
doi = {10.1103/PhysRevX.9.041044},
journal = {Physical Review X},
number = 4,
volume = 9,
place = {United States},
year = {2019},
month = {11}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1103/PhysRevX.9.041044

Save / Share: