The behavior of amorphous chalcogenide switching and memory devices is examined for the first time in an experiment which measures the acoustic response of a thermophonic cell enclosing an electrically pulsed device. The experiments employ coplanar samples made of memoryhyphen;type material. The cell response under single squarehyphen;pulse excitation is measured and the results are analyzed using techniques developed by Aamodt and Murphy. In general, under all bias conditions, analysis of our results indicates that the sample cools immediately after the switching event occurs. Under low ONhyphen;state power conditions, a large jump in microphone signal occurs at the switching transition. This is attributed to the current discharge driven by the large external circuit capacitance. There is a gradual reduction in the mirroring of the capacitive discharge as the ONhyphen;state power level is increased, suggesting that the discharge energy is used as a heat of transformation for melting formed (crystalline) regions, as well as for heating the conducting path.ForamemoryeventtooccuritisnecessarythattheONhyphen;statepowerbelargeenoughtopromotecrystallizationofthefilamentyetbelowenoughtoavoidmeltingtheconductingfilamentattheendofthepulse. In order to model the microphone signal and the temperature of the sample during switching, the analysis of Aamodt and Murphy is modified to allow for changes in the thermal conductivities of the sample and substrate. The posthyphen;switching volume is estimated using scanning electron microscopy, thereby allowing an estimation of the power density. The agreement between the experimental and computed curves is good.
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