Low density plasma-assisted electron and ion emission from LATGS single crystals

Energy distribution of plasma-assisted electron and ion emission from TGS single crystals

“…Up to now, however, the mechanism leading to the appearance of electron energy peak at 70-80 eV for second emission maximum has been unknown. Two maxima on the energy spectrum of electrons emitted under positive charging of the emitting surface due to the switching processes as well as mere charging of the sample were observed for L-a alanine doped TGS single crystals [19]. In conclusion, the TGS crystal sample subjected to the drive ac electric field of the order of 10 3 V/cm can produce electrons and ions as a results of the non-thermal surface plasma processes initiated during switching of the sample areas adjacent to the electrode.…”

“…It was reported earlier in [5,17] that under the influence of a drive ac electric field the TGS crystal samples can operate as a source of electrons with energies up to a few tens of eV and even the electron energies can be gained to about 200 eV [22]; under plasma-assisted surface processes the electrons and ions with energies up to a few hundred of eV can be produced on pure and La alanine doped TGS single crystals [17][18][19][20][21].…”

“…The measurements were conducted with the use of a PC and suitable data acquisition board [5,17,19]. Three channels in the A/D card were utilized to control the ac voltage supplied to the sample, exciting current and sawtooth-shaped voltage employed in a planar three-section energy analyzer.…”

“…The samples were supplied with vacuum evaporated Ag electrodes [19]. Before measurements the TGS samples were heated under vacuum of 10 À4 Pa up to about 350 K and next slowly cooled down to a chosen measuring temperature, i.e.…”

“…This problem is widely discussed in review paper given by Rosenman et al [16]. In the case of L-a alanine doped TGS (LATGS) crystals which have shown internal bias exceeding 10 3 V/cm, the electron emission processes were observed during negative as well as positive charging of the emitting sample surface due to switching of the spontaneous electric polarization, and also during normal charging of the dielectric sample [17][18][19]. The LATGS sample studied were excited by a drive 500 Hz ac electric field with amplitude higher than 5 Â 10 3 V/cm.…”