Browsing by Author "Deng, Liangzi"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
Item Fluorinated h-BN as a magnetic semiconductor(American Association for the Advancement of Science, 2017) Radhakrishnan, Sruthi; Das, Deya; Samanta, Atanu; de los Reyes, Carlos A.; Deng, Liangzi; Alemany, Lawrence B.; Weldeghiorghis, Thomas K.; Khabashesku, Valery N.; Kochat, Vidya; Jin, Zehua; Sudeep, Parambath M.; Martí, Angel A.; Chu, Ching-Wu; Roy, Ajit; Tiwary, Chandra Sekhar; Singh, Abhishek K.; Ajayan, Pulickel M.We report the fluorination of electrically insulating hexagonal boron nitride (h-BN) and the subsequent modification of its electronic band structure to a wide bandgap semiconductor via introduction of defect levels. The electrophilic nature of fluorine causes changes in the charge distribution around neighboring nitrogen atoms in h-BN, leading to room temperature weak ferromagnetism. The observations are further supported by theoretical calculations considering various possible configurations of fluorinated h-BN structure and their energy states. This unconventional magnetic semiconductor material could spur studies of stable two-dimensional magnetic semiconductors. Although the high thermal and chemical stability of h-BN have found a variety of uses, this chemical functionalization approach expands its functionality to electronic and magnetic devices.Item Vacancy-mediated anomalous phononic and electronic transport in defective half-Heusler ZrNiBi(Springer Nature, 2023) Ren, Wuyang; Xue, Wenhua; Guo, Shuping; He, Ran; Deng, Liangzi; Song, Shaowei; Sotnikov, Andrei; Nielsch, Kornelius; van den Brink, Jeroen; Gao, Guanhui; Chen, Shuo; Han, Yimo; Wu, Jiang; Chu, Ching-Wu; Wang, Zhiming; Wang, Yumei; Ren, ZhifengStudies of vacancy-mediated anomalous transport properties have flourished in diverse fields since these properties endow solid materials with fascinating photoelectric, ferroelectric, and spin-electric behaviors. Although phononic and electronic transport underpin the physical origin of thermoelectrics, vacancy has only played a stereotyped role as a scattering center. Here we reveal the multifunctionality of vacancy in tailoring the transport properties of an emerging thermoelectric material, defective n-type ZrNiBi. The phonon kinetic process is mediated in both propagating velocity and relaxation time: vacancy-induced local soft bonds lower the phonon velocity while acoustic-optical phonon coupling, anisotropic vibrations, and point-defect scattering induced by vacancy shorten the relaxation time. Consequently, defective ZrNiBi exhibits the lowest lattice thermal conductivity among the half-Heusler family. In addition, a vacancy-induced flat band features prominently in its electronic band structure, which is not only desirable for electron-sufficient thermoelectric materials but also interesting for driving other novel physical phenomena. Finally, better thermoelectric performance is established in a ZrNiBi-based compound. Our findings not only demonstrate a promising thermoelectric material but also promote the fascinating vacancy-mediated anomalous transport properties for multidisciplinary explorations.