Magnetic susceptibility and Faraday rotation in zirconium based fluoride glasses

The temperature dependences of the d.c. magnetic susceptibility and Verdet constant in two zirconium based fluoride glasses have been studied. One sample has as a minor constituent dysprosium which has a large magnetic moment that dominates the material's magnetic character. The second sample, containing a small amount of europium, shows both Van Vleck paramagnetism and a Curie-Weiss behaviour. The Curie-Weiss character is believed to come from small amounts of Zr3+ and/or Zr2+ produced during the sample's manufacturing process. An upper limit is placed on the amount of magnetic zirconium in the material.