Phase transitions in high-symmetry cd2Nb2O7single crystals of the pyrochlore family

Колпакова, Н. Н.; Wiesner, M.; Shul’pina, I. L.; Szcz̀epańska, L.; Piskunowicz, P.

doi:10.1080/00150199608210496

Cited by 7 publications

(10 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Nominally 'pure' single crystal samples of Cd 2 Nb 2 O 7 and those doped with Gd 3+ (<0.05 at.%) were studied in the temperature interval of 80 K < T < 300 K which included PTs at T s , T C and T inc (=86 K), with the phase below T inc specified as an incommensurate one [5]. The single crystals were grown by the flux method [1,12,13].…”

Section: Methodsmentioning

confidence: 99%

“…The different colours of the nominally 'pure' crystals of different batches (colourless, yellow, orange or redorange) are due to random substitution of transition-metal ions (TM) for Cd 2+ [12,14,15]. Nevertheless, for less than 0.1 at.% of the substituted ions, neither the sequence of PT in Cd 2 Nb 2 O 7 pyrochlore nor the PT temperature points change noticeably [5,6,12,14].…”

Section: Methodsmentioning

confidence: 99%

“…To elucidate these questions, a study of true thermally induced changes in the domain pattern and characterization of both ferroic states from the structure-instability viewpoint need to be performed. On the other hand, elucidation of the nature of the ferroic states and of their evolution on a temperature scale is also of great importance for understanding the mechanism responsible for coexistence of the ordered (ferroelectric) and disordered (relaxor, incommensurable, glassy) states in Cd 2 Nb 2 O 7 [5,6].…”

Section: Introductionmentioning

confidence: 99%

“…In nominally 'pure' Cd 2 Nb 2 O 7 , the phase transitions (PTs) to the ferroic states are second order [4,5,7]. Under uniaxial stress or external dc electric field, the PT at T s is a first-order PT close to the second-order one [3,4].…”

Section: Introductionmentioning

confidence: 99%

“…Under uniaxial stress or external dc electric field, the PT at T s is a first-order PT close to the second-order one [3,4]. From calorimetric studies, the PTs at T s and T C are of a mixed order-disorder and displacive character [5]. The displacive character of the PT at T C is also confirmed by the fact of the existence of the IR-active soft mode above T C and of the Raman-active soft mode below T C , with the characteristic frequency shift of the modes described as ω c ∼ (T C − T ) 0.5 [7,8].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

EPR spectroscopy and optical microscopy study of ferroic states in pyrochlore

Колпакова

Waplak

Bednarski

1998

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

The EPR spectroscopy (using as the EPR probe) and optical microscopy studies of pyrochlore were carried out in the temperature range of 80 K-300 K which included phase transitions at and . The evidence for coexistence of a proper ferroelectric-ferroelastic state and an improper ferroelectric-ferroelastic state in the ferroelectric phase of is presented. While the former appears below , the latter comes from the improper ferroelastic state of the precedent phase . The unusual behaviour of the ferroic states on a temperature scale is discussed from the viewpoint of a two-weakly-bonded-network description of the pyrochlore structure.

show abstract

Section: Methodsmentioning

confidence: 99%