Effect of annealing time on structural, optical and magnetic properties of TiO2 nanoparticles

被引：13

作者：

Theja, K. K.

Supin, K. K.

Akshay, V. R. ^{[1
,2
]}

Arun, B. ^{[1
,2
]}

Mandal, Guruprasad ^{[4
]}

Chanda, Anupama ^{[5
]}

Vasundhara, M. ^{[1
,2
,3
]}

机构：

[1] Natl Inst Interdisciplinary Sci & Technol, Mat Sci & Technol Div, CSIR, Trivandrum 695019, Kerala, India

[2] Acad Sci & Innovat Res AcSIR, Ghaziabad 201002, India

[3] CSIR Indian Inst Chem Technol, Polymers & Funct Mat Div, Hyderabad 500007, India

[4] Jadavpur Univ, Ctr Rural & Cryogen Technol, Kolkata 700032, India

[5] Dr Hari Singh Gour Cent Univ, Dept Phys, Sagar 470003, India

来源：

OPTICAL MATERIALS | 2022年 / 134卷

关键词：

TiO2; Room temperature ferromagnetism; Oxygen vacancy; Ti3+ions; Bound magnetic polaron; ROOM-TEMPERATURE FERROMAGNETISM; ANATASE TIO2; BAND-GAP; RAMAN-SPECTRUM; CU; NANOCRYSTALS; ENHANCEMENT; SIZE;

D O I：

10.1016/j.optmat.2022.113178

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The structural, optical and magnetic behavior of undoped TiO2 nanoparticles synthesized by sol-gel technique annealed at 400 degrees C in air for different time periods were studied. Tetragonal anatase phase was formed in all the samples as studied from X-ray diffraction, and Raman spectroscopy. HRTEM showed the particles in the nano -meter range (13-16 nm) Photoluminescence and XPS show the formation of oxygen vacancies and Ti3+ions. Clear hysteresis is observed at low field, but there is a lack of saturation magnetization, suggesting the presence of paramagnetic/diamagnetic contributions. The bound magnetic polaron (BMP) is proposed to be the mecha-nism of ferromagnetism (FM) which is formed by overlapping of orbital of trapped electrons in F+ center with the unpaired (3d1) electron of Ti3+ions. The increase of magnetic moment with the increase in annealing time can be due to a greater number of BMPs participating in FM exchange and the same have formed due to the formation of large number of oxygen vacancies and Ti3+ ions in TiO2 nanocrystals.

引用

页数：8

共 53 条

[1] Tailoring the NIR range optical absorption, band-gap narrowing and ferromagnetic response in defect modulated TiO2 nanocrystals by varying the annealing conditions [J].