Electronic Properties of Alkali Metals Loaded into Channel-Type Zeolite L

3rd International Conference on Functional Materials Science 2016

Thi, P.T.^1,2 ; Nakano, T.^2 ; Sakamoto, Y.^2,3 ; Nozue, Y.^2

Center for Innovative Materials and Architectures (INOMAR), Vietnam National University, Ho Chi Minh City (VNU-HCM), Quart 6, Linh Trung Ward, Thu Duc District, Ho Chi Minh City, Viet Nam^1

Department of Physics, Graduate School of Science, Osaka University, Toyonaka, Osaka

560-0043, Japan^2

Precursory Research for Embryonic Science and Technology (PRESTO), Japan Science and Technology Agency (JST), Kawaguchi, Saitama

332-0012, Japan^3

关键词: Confinement potential;    Loading density;    Metallic conductivity;    Metallic properties;    Metallic resistivity;    Reflection bands;    Temperature dependent;    Thermal activation energies;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/196/1/012002/pdf
DOI  :  10.1088/1757-899X/196/1/012002

来源: IOP

【 摘 要 】

Rb metal was loaded into dehydrated Rb-form zeolite L. The loading density of Rb atoms per unit cell, n, was changed up to 7.1. A resonant optical absorption-reflection band is observed at ≈1.0 eV in all samples. A new reflection band appears at ≈1.7 eV for n > 5. The 1.0 and 1.7 eV bands are assigned to the respective excitations from 1s to 1p and from 1p to 1d quantum states of s-electrons one-dimensionally confined in main-channels with an inside diameter of ≈1 nm. A temperature-dependent semiconducting resistivity is observed at n > 2, and is assigned to the inter-channel polaron hopping between metallic 1s and 1p states. Besides, a nearly metallic resistivity with the low thermal activation energy is observed at n > 5. The metallic conductivity is assigned to three-dimensional s-electrons in the 1d state. The metallic property in Rb-loaded zeolite L is more remarkable than those in K-loaded zeolite L. The difference is explained by the smaller ionization energy of Rb atom, which leads to a shallower one-dimensional confinement potential of main-channel and a smaller polaron effect.