engleski

Pyroelectric Temperature Analysis of Polycrystalline Ferroelectrics

In order to improve the recently proposed method for testing the ferroelectric activity of crystalline powder, a study of pyroelectric temperature analysis (PTA) for KH2PO4 has been made. The PTA curves obtained for the unsintered pressed powder in the ferroelectric temperature region indicated three different charge components. The first component, ahmE, is the continuously liberated homocharge induced by previous electric poling. The second one, ΔQom represents the charge released during the phase transition. It appears only in case of preferential orientation of crystal grains, and is independent of the poling procedure. The third component, a ht E, also occurs during the transition, but is induced only by poling. It appears as the heterocharge and is observed regardless of preferential orientation. The results have been compared to those obtained in analogous measurements with other polycrystalline materials as ferroelectric K4Fe(CN)6·3H2O, antiferroelectric NH4H2PO4, as well as nonferroelectric NaCl.

ferroelectric activity ; pyroelectric temperature analysis

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