中文摘要：

与均匀组分铁电薄膜相比，组分梯度铁电薄膜有很多优异的性能，其介电性能显著提高，从而有效改善了微波调谐器件的性能。上、下梯度铁电薄膜的性能也不相同，但目前尚无研究者从实验上证明其产生差异的原因。另外，组分梯度铁电薄膜的电滞回线的极化偏移仍然是一个比较有争议的问题。因此，研究组分梯度铁电薄膜在实际应用和完善理论研究方面均具有重要意义。综述了近年来对组分梯度铁电薄膜的研究进展并提出了研究中需要解决的问题。

英文摘要：

Compared with the homogeneous ferroelectrie thin films, the compositionally graded ferroelectric thin films have many excellent performances. The dielectric properties of the compositionally graded ferroelectric thin films are significantly enhanced. Therefore, the performance of the tunable microwave device applications is effectively improved. The properties of up and down graded ferroelectric thin films are also different. Howev- er, the cause of these differences has not been experimentally proved. In addition, the polarization offset of the hysteresis loop is still a controversial problem. Thus, researchers of compositionally graded ferroelectric thin films are of great significance both in the practical applications and the improvements of the theories. The arti- cle reviews the researches of compositionally graded ferroelectric thin films, and also proposes some problems needed to be solved.