Room‐Temperature Colossal Magnetoresistance in Terraced Single‐Layer Graphene. Issue 37 (2nd August 2020)

• Record Type: Journal Article
• Authors: Hu, Junxiong; Gou, Jian; Yang, Ming; Omar, Ganesh Ji; Tan, Junyou; Zeng, Shengwei; Liu, Yanpeng; Han, Kun; Lim, Zhishiuh; Huang, Zhen; Wee, Andrew Thye Shen; Ariando, Ariando
• Is Part Of: Advanced materials. Volume 32:Issue 37(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-08-02
• Subjects: 2D materials -- complex oxides -- disorder -- interfacial coupling -- magnetoresistance; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.202002201
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Disorder‐induced magnetoresistance (MR) effect is quadratic at low perpendicular magnetic fields and linear at high fields. This effect is technologically appealing, especially in 2D materials such as graphene, since it offers potential applications in magnetic sensors with nanoscale spatial resolution. However, it is a great challenge to realize a graphene magnetic sensor based on this effect because of the difficulty in controlling the spatial distribution of disorder and enhancing the MR sensitivity in the single‐layer regime. Here, a room‐temperature colossal MR of up to 5000% at 9 T is reported in terraced single‐layer graphene. By laminating single‐layer graphene on a terraced substrate, such as TiO2 ‐terminated SrTiO3, a universal one order of magnitude enhancement in the MR compared to conventional single‐layer graphene devices is demonstrated. Strikingly, a colossal MR of >1000% is also achieved in the terraced graphene even at a high carrier density of ≈10 12 cm −2 . Systematic studies of the MR of single‐layer graphene on various oxide‐ and non‐oxide‐based terraced surfaces demonstrate that the terraced structure is the dominant factor driving the MR enhancement. The results open a new route for tailoring the physical property of 2D materials by engineering the strain through a terraced substrate. Abstract : Terraced graphene, formed by laminating single‐layer graphene on a terraced substrate, shows a colossal magnetoresistance of up to 5000% at 9 T and 300 K. The magnetoresistance enhancement is attributed to the topographic corrugations and inhomogeneous charge puddles induced by the terraced structure. The concept of inducing colossal magnetoresistance by stepped surfaces is certainly boosting room‐temperature graphene magnetic sensors.