STRUCTURAL AND DYNAMICAL PROPERTIES OF A NEW FAMILY OF SOLID-SOLUTIONS - BAMN1-XZNXF4

The new solid solutions BaMn1-xZnxF4 have been investigated by differe nt experimental methods in the temperature range 10 K-300 K. X-ray and calorimetric measurements show that the incommensurate phase characte ristic of BaMnF4 is also observed for x less than or equal to 0.25. Ra man spectra were obtained for BaMn0.5Zn0.5F4 and BaMn0.25Zn0.75F4. Two low-frequency, temperature-dependent bands were observed over the who le temperature range investigated. These results are discussed in conn ection with structural disorder and the presence of precursor effects of an incommensurate phase transition.