Magnetic Properties of One- and Two-Dimensional Functional Materials: Oxygen Molecules Encapsulated in Single-Walled Carbon Nanotubes and Copper Ions Embedded into Phthalocyanine Sheets



Masayuki Hagiwara1, *, Takanori Kida1, Kazuyuki Matsuda2, Haruka Kyakuno2, Yutaka Mniwa3, Zentaro Honda4, Yuya Sakaguchi4, Makoto Tashiro4, Masamichi Sakai4, Takeshi Fukuda4, Norihiko Kamata4, Kouichi Okunishi5
1 Center for Advanced High Magnetic Field Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
2 Institute of Physics, Faculty of Engineering, Kanagawa University, Yokohama 221-8686, Japan
3 Department of Physics, Graduate School of Science and Engineering, Tokyo Metropolitan University, Hachioji 192-0397 , Japan
4 Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570, Japan
5 Department of Physics, Faculty of Science, Niigata University, Niigata 950-2181, Japan

Abstract

Background:

We report on two topics related to one-dimensional (1D)- and two-dimensional (2D) functional materials. Firstly, we describe magnetic properties of oxygen molecules having spin one (S=1) encapsulated in single-walled carbon nanotubes with an inner diameter of ca 0.8 nm.

Materials and Methods:

New functionality is expected to emerge in magnetic ions or molecules confined into nanospaces. This sample is one of such examples and shows magnetic properties of the S=1 1D Heisenberg antiferromagnet, the so-called Haldane magnet. The intrinsic magnetic susceptibility exhibits a broad maximum at around 50 K and decreases steeply with decreasing temperature. Nearly zero magnetization was observed up to the magnetic field of 10 T and then the magnetization increases almost linearly, which agrees well with the magnetization calculated for the S=1 Haldane magnet.

Results:

Accordingly, we have succeeded in preparing the Haldane magnet in an artificial manner. Secondly, the synthesis and magnetic properties of highly-ordered poly copper phthalocyanine (PCuPc) are reported. This material was prepared using copper octacyano-phthalocyanine and CuCl2·2H2O. When preparing the material without CuCl2·2H2O, we have found the formation of polymer network that consists of a 2D porous PCuPc sheet, in which the centers of phthalocyanine units are alternately occupied by Cu atom and vacancy.

Conclusion:

The formation of half-filling of Cu ions in the polymer network was confirmed by comparing its magnetic properties with those for almost Cu-full-filling polymer. This “half-filling” technique enables us to create alternating arrangements for transition metal centers, paving the way to control magnetic properties of the 2D carbon sheets.

Keywords: Oxygen molecules, Single-walled carbon nanotubes, Magnetic susceptibility, High-field magnetization, Copper phthalocianine, Half-filling.


Abstract Information


Identifiers and Pagination:

Year: 2019
Volume: 06
Publisher Item Identifier: EA-CHEM-2019-HT1-621-2

Article History:

Received Date: 13/1/2018
Revision Received Date: 3/3/2018
Acceptance Date: 27/1/2019
Electronic publication date: 11/02/2019
Collection year: 2019

© 2019 Hagiwara et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: (https://creativecommons.org/licenses/by/4.0/legalcode). This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Correspondence: Address correspondence to this author at the Department Center for Advanced High Magnetic Field Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan; Tel: +81-6-6850-6685; E-mails: hagiwara@ahmf.sci.osaka-u.ac.jp