Synthesis and physical properties of the hollandite-type titanium oxide KxTi8O16

Yuji Muraoka; Kengo Noami; Takanori Wakita; Masaaki Hirai; Takayoshi Yokoya; Yukako Kayo; Takayuki Muro; Yusuke Tamenori

doi:10.1002/pssc.201000383

Synthesis and physical properties of the hollandite-type titanium oxide K_xTi₈O₁₆

Yuji Muraoka, Kengo Noami, Takanori Wakita, Masaaki Hirai, Takayoshi Yokoya, Yukako Kayo, Takayuki Muro, Yusuke Tamenori

Research output: Contribution to journal › Article › peer-review

7 Citations (Scopus)

Abstract

Polycrystalline sample of hollandite-type titanium oxide K_xTi₈O₁₆ has been prepared and studied by magnetization and X-ray photoelectron spectroscopy (XPS). Room temperature ferromagnetic behaviour is observed in the magnetic hysteresis measurements. XPS measurements of the Ti 2p_3/2 core-level finds that the titanium ions take a mixed valence of Ti⁴⁺ and Ti³⁺. In addition, the valence band spectrum reveals that the 3d electrons tend to local-ize on Ti³⁺ ions in the hollandite-type TiO₂ lattice. Also, analysis of the valence band spectrum shows that the prepared sample is a wide-gap oxide with a band gap of 3.6 eV. These results indicate that the present hollandite-type K_xTi₈O₁₆ sample can be classified as a TiO₂-based wide-gap semiconductor with Curie temperature above room temperature.

Original language	English
Pages (from-to)	555-557
Number of pages	3
Journal	Physica Status Solidi (C) Current Topics in Solid State Physics
Volume	8
Issue number	2
DOIs	https://doi.org/10.1002/pssc.201000383
Publication status	Published - Feb 1 2011

Keywords

Ferromagnetism
Hollandite-type
TiO
XPS

ASJC Scopus subject areas

Condensed Matter Physics

Access to Document

10.1002/pssc.201000383

Cite this

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title = "Synthesis and physical properties of the hollandite-type titanium oxide KxTi8O16",

abstract = "Polycrystalline sample of hollandite-type titanium oxide KxTi8O16 has been prepared and studied by magnetization and X-ray photoelectron spectroscopy (XPS). Room temperature ferromagnetic behaviour is observed in the magnetic hysteresis measurements. XPS measurements of the Ti 2p3/2 core-level finds that the titanium ions take a mixed valence of Ti4+ and Ti3+. In addition, the valence band spectrum reveals that the 3d electrons tend to local-ize on Ti3+ ions in the hollandite-type TiO2 lattice. Also, analysis of the valence band spectrum shows that the prepared sample is a wide-gap oxide with a band gap of 3.6 eV. These results indicate that the present hollandite-type KxTi8O16 sample can be classified as a TiO2-based wide-gap semiconductor with Curie temperature above room temperature.",

keywords = "Ferromagnetism, Hollandite-type, TiO, XPS",

author = "Yuji Muraoka and Kengo Noami and Takanori Wakita and Masaaki Hirai and Takayoshi Yokoya and Yukako Kayo and Takayuki Muro and Yusuke Tamenori",

year = "2011",

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language = "English",

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T1 - Synthesis and physical properties of the hollandite-type titanium oxide KxTi8O16

AU - Muraoka, Yuji

AU - Noami, Kengo

AU - Wakita, Takanori

AU - Hirai, Masaaki

AU - Yokoya, Takayoshi

AU - Kayo, Yukako

AU - Muro, Takayuki

AU - Tamenori, Yusuke

PY - 2011/2/1

Y1 - 2011/2/1

N2 - Polycrystalline sample of hollandite-type titanium oxide KxTi8O16 has been prepared and studied by magnetization and X-ray photoelectron spectroscopy (XPS). Room temperature ferromagnetic behaviour is observed in the magnetic hysteresis measurements. XPS measurements of the Ti 2p3/2 core-level finds that the titanium ions take a mixed valence of Ti4+ and Ti3+. In addition, the valence band spectrum reveals that the 3d electrons tend to local-ize on Ti3+ ions in the hollandite-type TiO2 lattice. Also, analysis of the valence band spectrum shows that the prepared sample is a wide-gap oxide with a band gap of 3.6 eV. These results indicate that the present hollandite-type KxTi8O16 sample can be classified as a TiO2-based wide-gap semiconductor with Curie temperature above room temperature.

AB - Polycrystalline sample of hollandite-type titanium oxide KxTi8O16 has been prepared and studied by magnetization and X-ray photoelectron spectroscopy (XPS). Room temperature ferromagnetic behaviour is observed in the magnetic hysteresis measurements. XPS measurements of the Ti 2p3/2 core-level finds that the titanium ions take a mixed valence of Ti4+ and Ti3+. In addition, the valence band spectrum reveals that the 3d electrons tend to local-ize on Ti3+ ions in the hollandite-type TiO2 lattice. Also, analysis of the valence band spectrum shows that the prepared sample is a wide-gap oxide with a band gap of 3.6 eV. These results indicate that the present hollandite-type KxTi8O16 sample can be classified as a TiO2-based wide-gap semiconductor with Curie temperature above room temperature.

KW - Ferromagnetism

KW - Hollandite-type

KW - TiO

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