EPR Studies of the Low-Tempehature Phase Transitions in LiKSO₄by Cu²⁺Ions

Abstract

E l e c t r o n paramagnetic r e s o n a r c e (EPH) s p e c t r a of Cu2+ doped l i t hium potassium s u l p h a t e (LPY) l i m e been s t u d i e d at d i f f e r e n t tenipe r a t u r e s . 'She spin-1Iamiltoniai-i g and A p a r a m e t e r s have been evaluated. Phase t r a n s i t i o n s i n LPS were observed a t l o w temperature. The measured g-values i n d i c a t e a rhombic f i e l d f o r Cu2' i n t h e lat t i c e a t *he t e m p e r a t u r e range 300 -215 K. Between 215 IS and 123

Phase transitions in between 1.5 K and 850 K: an infrared spectroscopic study

“…The orientation and deformation of the SO 4 tetrahedra result in the different structures, so LiKSO 4 undergoes several phase transitions at high and low temperatures. Extensive studies on the phase transitions in LiKSO 4 have been carried out in past by a variety of measurements of physical parameters: specific heat (Abello et al 1985, Kassem et al 1994, electric properties (Breczewski et al 1981, Mróz et al 1982, Mendes et al 1986, Pimenta et al 1989, Desousa et al 1993, acoustic wave propagation (Borisov et al 1994, Gridnev and Khodorov 1996, thermal expansion (Prasad et al 1978), EPR (Dantas et al 1991, Hefni et al 1994, acoustic phonon frequencies (Mróz et al 1989, Czajkowski et al 1991, Raman active phonon dispersion (Hiraishi et al 1976, Bansal et al 1980, Teeters and Frech 1982, Ganot et al 1985, Mendes et al 1986, Oliveria et al 1988, Kim and Frech 1988, Dharmasena and Frech 1995, IR phonon frequencies (Hiraishi et al 1976, Pimenta et al 1986, Varma et al 1990, optical birefringence (Sorge and Hempel 1986, Leitão et al 1994, resonant ultrasound absorption 0953-8984/98/5011811+17$19.50 c 1998 IOP Publishing Ltd (Willis et al 1996), NMR (Topic et al 1988, Lim et al 1997, ESR (Holuj and Drozdowski 1981, Fonseca et al 1983, Perpétuo et al 1992, x-ray diffraction spectra (Tomaszewski and Lukaszewicz 1983…”