Ferroelectric storage device using gadolinium molybdate

Claim 2

A storage device comprising: a memory element including a stable irregular ferroelectric body composed of a crystal plate selected from a group of Gd2 (MoO4)3 single crystal and its crystallographic isomorphs and boracite which strains at the time of polarization reversal and is provided with a pair of electrodes on upper and lower surfaces thereof; a load connected in series with said memory element for detecting the change in polarization of said memory element; driving means for applying a write-in voltage pulse and a readout voltage pulse to the series connected circuit of said irregular ferroelectric body and said load, wherein said respective write-in voltage pulse and said readout voltage pulse each has a pulse height sufficient to cause the polarization reversal of said irregular ferroelectric body.

Claim 3

A storage device according to claim 1, wherein said irregular ferroelectric body consists of Gd2(MoO4)3.

Claim 4

A storage device according to claim 1, wherein said irregular ferroelectric body consists of crystallographic isomorph of Gd(MoO4)3.

Claim 5

A storage device according to claim 1, wherein said irregular ferroelectric body consists of boracite.

Claim 6

A storage device comprising: a plurality of memory elements arranged in rows and columns into a matrix shape wherein each memory element comprises a stable irregular ferroelectric body made of a GMO single crystal plate which strains at the time of polarization reversal and is provided with a plurality of electrodes on face and back surfaces thereof cut crosswise in mesh shape in two directions intersecting each other, said plurality of electrodes covering a mesh of said GMO single crystal plate at the place of each crossing point thereof, and wherein one of said pair of electrodes of said memory elements in each row of said matrix is connected commonly to form X-drive lines, respectively, and the other one of the pair of electrodes of said memory elements in each column of the matrix is connected commonly to foRm Y-drive lines, respectively; loads connected in series to Y-drive lines, respectively, for detecting the change in polarization of said memory element; and driving means for selectively applying two driving pulses of opposite polarity to one of the X-drive lines and to one of the Y-drive lines through said loads, respectively, the pulse height of each of said two driving pulses being insufficient to reverse the polarization of said irregular ferroelectric body, while a superimposed pulse height of said two driving pulses is sufficient to reverse the polarization of said irregular ferroelectric body.

Claim 7

A storage device comprising: a plurality of memory elements arranged in rows and columns into a matrix shape wherein each memory element comprises a stable irregular ferroelectric body made of a GMO single crystal plate which strains at the time of polarization reversal and is provided with a plurality of electrodes on face and back surfaces thereof cut crosswise in mesh shape in two directions intersecting each other, said plurality of electrodes covering a mesh of said GMO single crystal plate at the place of each crossing point thereof, and wherein one of said pair of electrodes of said memory elements in each row of said matrix is connected commonly to form X-drive lines, respectively, and the other one of the pair of electrodes of said memory elements in each column of the matrix is connected commonly to foRm Y-drive lines, respectively; loads connected in series to Y-drive lines, respectively, for detecting the change in polarization of said memory element; and driving means for selectively applying two driving pulses of opposite polarity to one of the X-drive lines and to one of the Y-drive lines through said loads, respectively, the pulse height of each of said two driving pulses being insufficient to reverse the polarization of said irregular ferroelectric body, while a superimposed pulse height of said two driving pulses is sufficient to reverse the polarization of said irregular ferroelectric body.