学术报告通知

Division of Physical Science and Engineering, King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Kingdom of Saudi Arabia

 

Positive and near-temperature-independent linear magnetoresistance, as large as 440%, was observed in graphene foam with a three-dimensional flexible network. Careful analysis of its magnetoresistance revealed that Shubnikov-de Hass (SdH) oscillations occurred at low temperatures and decayed with increasing temperature. The average classical mobility derived from the Hall Effect measurement ranged from 300 (2 K) to 150 (300 K) cm²V^-1s^-1, which is much smaller than that required by the observed SdH oscillations. To understand the  mechanism behind the observation, we have performed the same measurements on the micro-sized  samples with help of e-beam lithography.  Much more pronounced SdH oscillations superimposed on the linear magnetoresistance background are observed in these micro-scaled samples, which corresponds to a quantum mobility as high as . The presence of SdH oscillations actually excludes the possibility that the observed linear magnetoresistance originates from the extreme quantum limit, because it demands all electrons to be in the first Landau level. Instead, we ascribed the large LMR to the second case of the classical Parish and Littlewood (PL) model, in which mobility fluctuation dominates electrical transport.

 

 

 

Division of Physical Science and Engineering

King Abdullah University of science and Technology

Saudi Arabia

Tel: +96628082332

E-mail: xixiang.zhang@kaust.edu.sa

 

First Name: XIXIANG                 Family Name: ZHANG

Sex: Male                                   Citizenship: Hong Kong SAR China

 

 

Ph. D. ----1992, Universitat de Barcelona, Spain.

M. S. -----1986, Tianjin University, China.

BS --------1983, Tianjin University, China.

 

 

·         Division of Physical Science and Engineering, King Abdullah University of science and Technology

Jan. 2014-

Professor

 

·         Research and Graduation Education, King Abdullah University of science and Technology, Aug. 2012-Feb. 2014

Director of Core Labs

 

·         Research and Research, King Abdullah University of science and Technology

Sept.2008-July, 2013

Manager of Core labs: 1) Nanofabrication; 2) Imaging –characterization, 3) Thin films

 

·         Dept. of Phys., The Hong Kong Univ. of Sci. and Tech., Aug. 1997- Oct.  2009

Assistant Professor/ Associate Professor/Professor

 

·         Dept. de Fisica Fonamental, Universitat de Barcelona, Spain 1995-Aug. 1997

Senior research scientist

 

·         Dept. de Fisica Fonamental, Universitat de Barcelona, Spain,1/1994 ---12/994

      Research Scientist

 

·         Dept. de Fisica Fonamental, Universitat de Barcelona, Spain, 1/1993-- 12/1993

Research scientist: Fellowship  Sabbatical from "Ministry of Education and Science, Spain"

 

·         Dept. de Fisica Fonamental, Universitat de Barcelona, Spain, 1/1991-   12/1992

Research scientist: Fellowship from "Ministry of Education and Science, Spain"

 

·         Dept.  of Physics, Tianjin University, China, 1988-1990

Lecture

 

·         Dept.  of  Physics, Tianjin University, China, 1986--1988

Assistant (teacher)

 

 

6.     "Discovery and mechanism of LaFeSi based magnetocaloric materials , No. 905-     2010-001"  First Prize of Beijing City in Science and Technology, 2011.

       " 新型LaFeSi基等磁热效应材料的发现和磁热机理研究；项目编号905-2010-      001"  2011年度北京市科学技术一等奖，

 

7.   " Discovery and investigation of novel magnetocaloric effect materials, 2012-Z-108-     2-03-R04" State Natural Science Award (Second Class), 2012.

       国家自然科学奖，二等，证书号：2012-Z-108-   2-03-R0