Colossal Magnetization and Giant Coercivity in Ion-Implanted (Nb and Co) MoS2 Crystals

Sohail Ahmed; Xiang-Yuan Carl Cui; Xiang Ding; Peter Paul Murmu; Nina Bao; Xun Geng; Shibo Xi; Rong Liu; John Kennedy; Tom Wu; Lan Wang; Kiyonori Suzuki; Jun Ding; Xueze Chu; Sathish Russellraj Clastinrusselraj Indirathankam; Mingli Peng; Ajayan Vinu; Simon Peter Ringer; Jiabao Yi

doi:10.1021/acsami.0c18150

Colossal Magnetization and Giant Coercivity in Ion-Implanted (Nb and Co) MoS₂ Crystals

ACS Appl Mater Interfaces. 2020 Dec 30;12(52):58140-58148. doi: 10.1021/acsami.0c18150. Epub 2020 Dec 16.

Authors

Sohail Ahmed¹, Xiang-Yuan Carl Cui², Xiang Ding^{1

3}, Peter Paul Murmu⁴, Nina Bao⁵, Xun Geng¹, Shibo Xi⁶, Rong Liu⁷, John Kennedy⁴, Tom Wu¹, Lan Wang⁸, Kiyonori Suzuki⁹, Jun Ding⁵, Xueze Chu¹⁰, Sathish Russellraj Clastinrusselraj Indirathankam¹⁰, Mingli Peng¹¹, Ajayan Vinu¹⁰, Simon Peter Ringer², Jiabao Yi¹⁰

Affiliations

¹ School of Materials Science and Engineering, UNSW, Sydney, New South Wales 2052, Australia.
² Australian Centre for Microscopy & Microanalysis, and School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, Sydney, New South Wales 2006, Australia.
³ School of Energy and Power Engineering, Wuhan University of Technology, Wuhan, Hubei 430063, China.
⁴ National Isotope Centre, GNS Science, P.O. Box 31312, Lower Hutt 5010, New Zealand.
⁵ Department of Materials Science and Engineering, National University of Singapore, 119260, Singapore.
⁶ Institute of Chemical and Engineering Sciences, A*STAR, 1 Pesek Road, Jurong Island, 627833, Singapore.
⁷ SIMS Facility, Office of the Deputy-Vice Chancellor (Research and Development), Western Sydney University, Locked Bag 1797, Penrith, New South Wales 2751, Australia.
⁸ School of Science, RMIT University, Melbourne, Victoria 3001, Australia.
⁹ Department of Materials Science and Engineering, Monash University, Clayton, Victoria 3800, Australia.
¹⁰ Global Innovative Centre for Advanced Nanomaterials, School of Engineering, The University of Newcastle, Callaghan, New South Wales 2308, Australia.
¹¹ Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710069, China.

PMID: 33375795
DOI: 10.1021/acsami.0c18150

Abstract

Colossal saturation magnetization and giant coercivity are realized in MoS₂ single crystals doped with Nb and/or Co using an ion implantation method. Magnetic measurements have demonstrated that codoping with 2 at % Nb and 4 at % Co invoked a "giant" coercivity, as high as 9 kOe at 100 K. Doping solely with 5 at % Nb induces a "colossal" magnetization of 1800 emu/cm³ at 5 K, which is higher than that of metallic Co. The high magnetization is due to the formation of Nb-rich defect complexes, as confirmed by first-principles calculations. It is proposed that the high coercivity is due to the combined effects of strong directional exchange coupling induced by the Nb and Co doping and pinning effects from defects within the layered structure. This high magnetization mechanism is also applicable to 2D materials with bilayers or few layers of thickness, as indicated by first-principles calculations. Hence, this work opens a potential pathway for the development of 2D high-performance magnetic materials.

Keywords: 2D materials; MoS2; coercivity; first-principles calculations; magnetization.