Magnetic local-moment effects in the quasi-one-dimensional conductor Cu(triazatetrabenzporphyrinato)I

Magnetic moments located on the ${\mathrm{Cu}}^{2+}$ metal spine in the quasi-one-dimensional conductor Cu(tatbp)I(tatbp=triazatetrabenzpor- phyrinato) are found to have dramatic effects on the microwave conductivity and dielectric constant. Below 90 K the conductivity decreases by 3 orders of magnitude and slightly increases with magnetic field; this may be consistent with an independent Kondo impurity regime for a one-dimensional conductor. For T<6 K the microwave conductivity is enhanced in comparison to the dc one and it generally decreases with the field; over the same range the dielectric constant increases with the field. These effects, which have previously been correlated with a relaxation of the local moments observed in EPR, are attributed to dielectric losses.