Comparison of electrical and dielectric properties of BLSF materials in Bi-Fe-Ti-O and Bi-Mn-Ti-O systems

Compounds having the BLSF structure are interesting in view of their ferroelectric properties and also various applications. These are Aurivillius phases having the general formula (Bi2O2)(2+) (A(n-1)B(n)O(3n+1))(2-) where A represent the 12-fold coordinated cation with low valancies in the perovskite sub lattice; B denotes the octahedral site having ions of high valancies and n is the number of perovskite layers between the ( Bi2O2) 2+ layers along the c-axis. A number of compounds in the system Bi-Fe-Ti-O have been synthesized in our laboratory and studied earlier for their electrical, dielectric, magnetic and magnetoelectric properties. By replacing Fe with Mn, we have synthesized Bi5MnTi3O15, Bi6Mn2Ti3O18, Bi7Mn3Ti3O21, Bi8Mn4Ti3O24 and Bi9Mn5Ti3O27. These compounds have been studied for their structure, electrical, dielectric and pyroelectric properties. This paper reports the data on the physical properties of Mn containing compounds and a comparison is made with those similar compounds having Fe.