Lattice vibrational property in the transition-metal diboride ZrB2.
Lattice vibrational property has been determined in ZrB(2) system using the temperature-dependent extended X-ray-absorption fine-structure (EXAFS) technique from room temperature to 28K. The smooth behavior of Debye-Waller factor curve with temperature is slightly abnormal for the first pair Zr-B. In order to reproduce this curve, an improved Einstein mode with two Einstein frequencies has been used. The quantitative analysis of temperature-dependent Debye-Waller factor of Zr-B pair shows one Einstein frequency is very high and the other is small. These frequencies correspond to the vibration of boron layer atoms and transition-metal layer atoms, respectively. Based on the Einstein mode with one frequency, the vibrational frequency for Zr-Zr pair has been also obtained. Zirconium diboride has two types of Zr-Zr interaction. One is in-plane and the other is out-of-plane along the high symmetry axis. Our analysis shows there is a little difference between in-plane Zr-Zr vibration and out-of-plane one. And the smaller Einstein vibrational frequency for the Zr-B shell is just between the two ones of the Zr-Zr shells. Our results show that the lattice vibrational behavior in ZrB(2) presents obvious particularity and anisotropy.
Chu
W S
WS
Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China.
Wu
Z Y
ZY
Bianconi
A
A
Saini
N L
NL
Marcelli
A
A
Liu
W H
WH
D001896:Boron Compounds / Q000737:chemistry*; D005583:Fourier Analysis; D013057:Spectrum Analysis; D013696:Temperature; D028561:Transition Elements / Q000737:chemistry*; D014732:Vibration; D015040:Zirconium / Q000737:chemistry*
D001896:Boron Compounds; D028561:Transition Elements; C531301:zirconium diboride; D015040:Zirconium