Low Dimensionality Observed by ESR Measurements in<i>S</i>=1 Spin Ladder Substance BIP-TENO (3,3^′,5,5^′-tetrakis(<i>N</i>-tert-butylaminoxyl)biphenyl)

Abstract

X-band ESR measurements of BIP-TENO (3,3 ′ ,5,5 ′ -tetrakis( N -tert-butylaminoxyl)biphenyl) single crystal, which is an S =1 spin ladder model substance, have been performed in the temperature region from 3.5 to 300 K. At room temperature, the angular dependences of g -value and line width were observed. The line shape and the angular dependence of the line width showed typical behavior of a low-dimensional antiferromagnet. The temperature dependence measurements showed the minimum of the line width and the dynamical g -shift, which were also typical behaviors of a low-dimensional antiferromagnet. However, the direction of the dynamical g -shift does not coincide with Nagata's well-known theory, and the comparison with the recent direct ESR calculation by Miyashita et al. [S. Miyashita, T. Yoshino and A. Ogasahara: J. Phys. Soc. Jpn. 68 (1999) 655] is discussed.