Effect Of Texture On The Effective Moduli Of Ferroelectric Thin Films

Ferroelectric materials,for the ferroelectric and piezoelectric characteristics,have been widely applied in many fields,such asinformation memory,communication,navigation,accurate measurement,and machinery．With the development of microelectronic technologyand high integration,people need ferroelectric films with the sameproperties of bulk ferroelectric material,and researches on preparationand properties of ferroelectric thin film have become research subj ects． Ferroelectric films often emst as polycrystals and their properties areaffected by both of single crystal properties and crystallographicorientation．Due to anisotropy of PZT crystals,both of physical andelectrical properties for PZT thin films are expected to strongly dependupon the crystallographic orientation．In experiment,people have beenmaking effort to prepare thin film with high-preferred orientation inorder to improve the properties of thin film．On the other hand,in orderto guide the preparation of thin film people have been theoreticallystudying the effect of orientation on the properties ofthin film．It is veryimportant for researchers to prepare the film with high-preferredorientation and study orientation effect on film properties． In this paper,we firstly reviewed the potential application,excellent properties,preparation methods and the research status offerroelectric thin film material,meanwhile the dissertation topic WaSproposed．Secondly,the lead zirconate titanate(PZT)thin film WaSprepared by metal—organic decomposition(MOD)method．Thirdly,crystallographic orientation dependence on physical properties ofepitaxial PZT thin films was predicted by Voigt average model,andtexture effect on the properties of polycrystals PZT thin film wasdiscussed．The distribution factor was calculated by XRD and ratio ofremanence—to—saturation polarization,and the piezoelectric constantsand the dielectric constants were obtained．The pole figures ofPZT thin films were measured with X-ray texture diffractometer,and the effect ofdrying temperature for pyrolysis on texture was investigated．It wasreason that the amount of organic residue affects the nucleation andgrowth of grains,and texture of thin film．The piezoelectric anddielectric constants of PZT thin films with different orientations andthickness were evaluated by inverse pole—figures method．The resultsshow that piezoelectric constants of(00 1)一oriented films are larger thanthat of (111)-oriented films,but the dielectric constantε33 of(111)-oriented films are higher than that of(001)-oriented films．Thepiezoelectric constant d33 ofthe thin film with 1．5 U m was larger thanthat ofthe thin film with 0．8 U m,however the dielectric constantε33 wascontrary to that．...