Magnetism in TiO2 from ab initio perspective

a 2023

Magnetism in TiO2 from ab initio perspective

FRIÁK, Martin; Quynh Nhu Thi TRAN; Kristýna GAZDOVÁ; Jana PAVLŮ; Dominik MUNZAR et al.

Základní údaje

Originální název

Magnetism in TiO2 from ab initio perspective

Autoři

FRIÁK, Martin; Quynh Nhu Thi TRAN; Kristýna GAZDOVÁ; Jana PAVLŮ ; Dominik MUNZAR a Hoa Hong NGUYEN

Vydání

Accelerated Discovery of New Materials (Wilhelm and Else Heraeus-Foundation – Seminar, Psi-k), 2023

Další údaje

Jazyk

angličtina

Typ výsledku

Konferenční abstrakt

Obor

10403 Physical chemistry

Stát vydavatele

Německo

Utajení

není předmětem státního či obchodního tajemství

Označené pro přenos do RIV

Ano

Kód RIV

RIV/00216224:14310/23:00133887

Organizační jednotka

Přírodovědecká fakulta

Klíčová slova anglicky

Density functional theory; Quantum mechanical calculations; Spintronics; TiO2; Ferromagnetism; Crystallographic defects;

Změněno: 24. 3. 2024 23:03, doc. Mgr. Jana Pavlů, Ph.D.

Anotace

V originále

We present a combined experimental and theoretical study of surface-related magnetic states in TiO2. Our experiments on nano-sized thin films of pure TiO2 have suggested that the observed room-temperature magnetism originates from defects, in particular, from the surface of thin films as well as from point defects, such as oxygen vacancies located mainly at the surface. Since verifying this issue is very important to be able to manipulate the magnetic properties of pristine TiO2 films for future spintronic applications, certain conclusions from theoretical work is very demanding. Therefore, quantum-mechanical density functional theory (DFT) calculations were subsequently performed for (i) bulk anatase TiO2, (ii) bulk-like TiO2-terminated vacancy-free (001) surfaces, (iii) vacancy-containing TiO-terminated (001) surfaces, (iv) TiO_0.75-terminated (001) surfaces with additional 25% surface oxygen vacancies, as well as (v) oxygen-terminated (001)-surfaces. Our fixed-spin-moment calculations identified both the bulk and the bulk-like terminated vacancy-free TiO2-terminated (001) surfaces as non-magnetic. In contrast, oxygen vacancies in the case of TiO-terminated and TiO_0.75-terminated (001) surfaces lead to ferromagnetic and rather complex ferrimagnetic states, respectively. The spin-polarized atoms are the Ti atoms (due to the d-states) located in the surface and sub-surface atomic planes. Lastly, the O-terminated surfaces are also magnetic due to the surface and sub-surface oxygen atoms and sub-surface Ti atoms (but their surface energy is high).

Návaznosti

MUNI/A/1298/2022, interní kód MU

Název: Základní a aplikovaný výzkum a vývoj metod chemické a fyzikálně chemické analýzy pro studium přírody a pokročilé technologie

Investor: Masarykova univerzita, Základní a aplikovaný výzkum a vývoj metod chemické a fyzikálně chemické analýzy pro studium přírody a pokročilé technologie

90140, velká výzkumná infrastruktura

Název: e-INFRA CZ

Citovat

FRIÁK, Martin; Quynh Nhu Thi TRAN; Kristýna GAZDOVÁ; Jana PAVLŮ; Dominik MUNZAR a Hoa Hong NGUYEN. Magnetism in TiO2 from ab initio perspective. In Accelerated Discovery of New Materials (Wilhelm and Else Heraeus-Foundation – Seminar, Psi-k). 2023.

@proceedings{2387158,
   author = {Friák, Martin and Tran, Quynh Nhu Thi and Gazdová, Kristýna and Pavlů, Jana and Munzar, Dominik and NGUYEN, Hoa Hong},
   booktitle = {Accelerated Discovery of New Materials (Wilhelm and Else Heraeus-Foundation – Seminar, Psi-k)},
   keywords = {Density functional theory; Quantum mechanical calculations; Spintronics; TiO2; Ferromagnetism; Crystallographic defects;},
   language = {eng},
   title = {Magnetism in TiO2 from ab initio perspective},
   year = {2023}
}

TY  - CONF
ID  - 2387158
AU  - Friák, Martin - Tran, Quynh Nhu Thi - Gazdová, Kristýna - Pavlů, Jana - Munzar, Dominik - NGUYEN, Hoa Hong
PY  - 2023
TI  - Magnetism in TiO2 from ab initio perspective
KW  - Density functional theory
KW  - Quantum mechanical calculations
KW  - Spintronics
KW  - TiO2
KW  - Ferromagnetism
KW  - Crystallographic defects;
N2  - We present a combined experimental and theoretical study of surface-related magnetic states in TiO2. Our experiments on nano-sized thin films of pure TiO2 have suggested that the observed room-temperature magnetism originates from defects, in particular, from the surface of thin films as well as from point defects, such as oxygen vacancies located mainly at the surface. Since verifying this issue is very important to be able to manipulate the magnetic properties of pristine TiO2 films for future spintronic applications, certain conclusions from theoretical work is very demanding. Therefore, quantum-mechanical density functional theory (DFT) calculations were subsequently performed for (i) bulk anatase TiO2, (ii) bulk-like TiO2-terminated vacancy-free (001) surfaces, (iii) vacancy-containing TiO-terminated (001) surfaces, (iv) TiO_0.75-terminated (001) surfaces with additional 25% surface oxygen vacancies, as well as (v) oxygen-terminated (001)-surfaces. Our fixed-spin-moment calculations identified both the bulk and the bulk-like terminated vacancy-free TiO2-terminated (001) surfaces as non-magnetic. In contrast, oxygen vacancies in the case of TiO-terminated and TiO_0.75-terminated (001) surfaces lead to ferromagnetic and rather complex ferrimagnetic states, respectively. The spin-polarized atoms are the Ti atoms (due to the d-states) located in the surface and sub-surface atomic planes. Lastly, the O-terminated surfaces are also magnetic due to the surface and sub-surface oxygen atoms and sub-surface Ti atoms (but their surface energy is high).
ER  -

FRIÁK, Martin; Quynh Nhu Thi TRAN; Kristýna GAZDOVÁ; Jana PAVLŮ; Dominik MUNZAR a Hoa Hong NGUYEN. Magnetism in TiO2 from ab initio perspective. In \textit{Accelerated Discovery of New Materials (Wilhelm and Else Heraeus-Foundation – Seminar, Psi-k)}. 2023.

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