Effect of external fields on the memory effect of the incommensurate phase in the ferroelectric-semiconductor TlGaSe2

Modification of the optical and elastic properties of TlGaSe2 layered semiconductor produced by the memory effect

“…energy bandgaps of the annealed B1 sample. In previous work, a strong influence of the memory effect on the linear thermal -expansion coefficients of the pristine TlGaSe 2 has been reported [27,29,30,[65][66][67][68]. The comparison of the thermalexpansion results [27,29,[65][66][67][68] was deemed necessary to consider the contribution of volume dilation effect to the optical band gaps of annealed B1 sample.…”

“…In previous work, a strong influence of the memory effect on the linear thermal -expansion coefficients of the pristine TlGaSe 2 has been reported [27,29,30,[65][66][67][68]. The comparison of the thermalexpansion results [27,29,[65][66][67][68] was deemed necessary to consider the contribution of volume dilation effect to the optical band gaps of annealed B1 sample. Obviously, that at s ~1, the second term of equation (9) related to thermal expansion of the crystal lattice mainly provides a linear temperature narrowing of ( ) E T…”

“…Although the exact experimental evidence of DDW in TlGaSe 2 is still a matter of much debate, the changes in the chemical and physical (structural, optical, dielectric, electronic etc) properties of compounds achieved by the memory effect have been reported by various techniques [25][26][27][28][29][30]. Configurations from both fully and/or randomly frozen localized defect states could play a dominant role for obtaining of a new structural metastable phase of matter at the nanoscale within TlGaSe 2 ferroelectric -semiconductor with van der Waals interactions between the layers.…”

PRESSURE BEHAVIOUR OF DIELECTRIC PERMEABILITY IN TlGaSe2 CRYSTALS

“…Äîñë³äaeåííÿ ³íäóêîâàíèõ òèñêîì ô³çè÷íèõ åôåêò³â ó ñêëàäíèõ ôåðî¿êàõ ð³çíî¿ âèì³ðíîñò³ äàþòü ìîaeëèâ³ñòü ãëèáøå ïðîíèêíóòè â ïðèðîäó âèíèêíåííÿ íåñï³âì³ðíî-ìîäóëüîâàíèõ ñòðóêòóð ³ ïîÿâè íà ¿õ ä³àãðàìàõ ñòàíó ïîë³êðè-òè÷íèõ òî÷îê òà äîçâîëÿþòü ö³ëåñïðÿìîâàíî ïðîâîäèòè ïîøóê ìàòåð³àë³â äëÿ ðîçðîáêè íà ¿õ îñíîâ³ ôóíêö³îíàëüíèõ åëåìåíò³â äëÿ âèì³-ðþâà÷³â òèñêó, òåìïåðàòóðè, ï³ðîåëåêòðè÷íèõ ïðèéìà÷³â åëåêòðîìàãí³òíîãî âèïðîì³íþâàííÿ. Äî òàêîãî êëàñó ìàòåð³àë³â íàëåaeàòü ³ øàðó-âàò³ êðèñòàëè TlGaSe 2 , â ÿêèõ ³ñíóº íåñï³âì³ðíà ôàçà ó ³íòåðâàë³ òåìïåðàòóð 107-116 Ê [1][2][3][4].…”