(1797 - 1879)
Sociólogo, historiador y economista. Se destacó por su postura opuesta a la esclavitud y contra la anexión de Cuba a los Estados Unidos.
Natural and Exact Sciences
2001 | Ferroelectric Ceramics type PZT and PT modified with strange earths and transition elements
Main author: Oscar Pérez Martínez.

It is presented a result summary on how to obtain piezoelectric ceramics modified by elements from strange and transition earth. Many of the compositions presented, have been reported for the first time by the authors. These types of ceramics have a great application field in branches such as the ultrasound, which includes sensors for their use in medicine and for non-destructive tests.The systems based on lead, such as PZT and PT have been studied for many years, with different dopers that influence their piezoelectric properties, and from these, those linked to anisotropy have reached a remarkable relevance for their influence in the good resolution of medical images equipment.

Transition elements and strange earths were used as dopers in this research, which had not been used so far. This novel idea has allowed a deeper understanding of polarization mechanisms in piezoelectric materials and it has made possible establishing a relationship among the solid's crystalline structure and the properties of interest that it shows. It also made possible answering phenomena that lacked convincing physical interpretations such as: fatigue phenomena, anomalies and classification of phase transitions in ferroelectric material, as well as piezoelectricity's anisotropic behavior in titanate of modified lead. There were obtained ceramics with good properties for the generation and reception of ultrasound to high frequency and for applications such as infrared sensors.

The results of this collective of authors are reported in two doctorate theses, (one of them was chosen among the best results defended in the University of Havana (UH) in 2001) and 17 publications in the last 4 years, 16 of them published in prestigious specialized magazines such as: Journal of Material Sciences, Applied Physics Letters, Journal of Europpean Ceramic Society, Solid State Communications, published by Wiley, Pergamon and Elsevier. The authors have also received three applications from two important and internationally prestigious Databases, interested in gathering the data obtained in this work of Experimental Physics. These are the Database of the Center of Information for Strange Earths of Ames Laboratory in the United States and that of the International Center for Diffraction Data in Pensylvania.