Structural Changes In Chlorine-Substituted Sbsi

The antimony sulphoiodide (SbSI) is considered a prospective and important ferroelectric material due to its unique properties below Curie temperature T-c. However, the fact that current practical applications require higher working temperatures has prompted new structural improvements that extend the ferroelectric state. In this ternary system, T-c is highly sensitive to any chemical modifications or stress. Therefore, one way to adjust the T-c is through selective substitution of the constituent elements. In this work, SbSI has been fractionally chlorine-substituted at the iodine site and examined using temperature-dependent x-ray diffraction and specific heat capacity methods. Although a considerable increase in T-c has been achieved, a more detailed analysis shows that the T-c increases with x from 0 to 0.2 and starts to decrease when x > 0.2. The maximum T-c increase in the range of x = 0-0.3 is similar to 15.3%. The reverse behavior, from increase to decrease, is thoroughly discussed with reference to the previously published data on SbSI1-xClx compounds.