Coexistence of paraelectric/proton-glass and ferroelectric (antiferroelectric) orders in Rb₁₋x(NH₄)xH₂AsO₄ crystals

This paper reviews the results of dielectric studies of the proton glass state in a mixed crystal Rubidium Ammonium Dihydrogen Arsenate (RADA) The coexistence of paraelectric/proton glass and ferroelectric or antiferroelectric orders, confirmed by other studies, has been discussed in detail. The phase diagram of RADA is asymmetric. The proton glass state exists for ammonium concentration in the range of 0.1 < x < 0.5 . The phase diagram of deuterated DRADA is presented. The proton glass state region in DRADA, 0.2 < x < 0.35 is narrower than that for non-deuterated RADA. The effects of hydrostatic pressure on the dielectric properties in the proton glass state are presented. The glass temperature Tg decreases with pressure and is expected to vanish at 5 kbar. Low temperature behaviour is still an open question, since there is no experimental evidence of Tg(p) dependence below 4K for proton glass systems.Ця стаття є оглядом результатів діелектричного вивчення стану протонного скла у змішаних кристалах Rb₁₋x(NH₄)xH₂AsO₄ (RADA).Співіснування впорядкувань параелектричного/протонне скло та сегнетоелектричного чи антисегнетоелектричного, підтверджене іншими дослідженнями, детально обговорюється. Фазова діаграма RADA є асиметричною. Стан протонного скла існує для концентрації аміаку в межах 0, 1 < x < 0, 5 . Представлена фазова діаграма дейтерованого DRADA. Область стану протонного скла в DRADA (0, 2 < x < 0, 35) є вужчою, ніж у недейтерованому RADA. Представлені ефекти впливу гідростатичного тиску на діелектричні властивості кристалу в стані протонного скла. Температура склування Tg спадає з тиском і за оцінками прямує до нуля при 5 кбар. Низькотемпературна поведінка є все ще дискусійною, оскільки немає експериментально підтвердженої Tg(p) залежності нижче 4 К для систем протонного скла

Supplemental Material of the article Weak low-temperature polarity in a PbZrO3 single crystal

Supplement Material 1 describes in detail the experimental techniques used. -- Supplement Material 2 presents a film showing changes in indicatrix orientations during the low-temperature transition in PbZrO3 single crystals.Weak low-temperature_supplementary_material_1.pdfPeer reviewe

Weak low-temperature polarity in a PbZr O3 single crystal

We report the existence of a low-temperature polar phase in PbZrO3 below 270 K. The temperature dependence of resultant polarization was assigned from pyroelectric current changes measured after poling the single crystal or ceramic in a DC electric field. This was observed in single crystals and ceramics and may have a connection with the presence of polar (ferrielectric) antiphase boundaries inside the antiferroelectric phase. The transition point is demonstrated by changes in domain structure and anomalies in dielectric permittivity and losses in as-grown single crystals and ceramic samples.This research was funded by the National Science Centre, Poland, with Grant No. 2020/37/B/ST3/02015.Peer reviewe

EPR Study of Fe3+\text{}^{3+} Paramagnetic Centers in Doped Triglycine Sulphate Crystals

This paper presents EPR study of Fe$\text{}^{3+}$ in triglycine sulphate doped with Fe$\text{}^{3+}$ crystal. Fe$\text{}^{3 +}$ ion is in a high spin state S=5/2. EPR signal can be detected only below 200 K. At 4.2 K the EPR spectrum results from three non-equivalent sites of Fe$\text{}^{3+}$ ions. The spin Hamiltonian: H=β BĝS+D[S$\text{}_{z}^{2}$-(1/3)S(S+1)]+E(S$\text{}_{x}^{2}$-S$\text{}_{y}^{2}$) has been applied to describe the spectrum. The zero field splitting parameter in this case fulfills the condition: D≫hν. An experimental spectrum reflects clearly only two resonance transitions: |±1/2ã (the lowest Kramers doublet) and |±3/2〉 (the middle Kramers doublet). The iron complexes occupy interstitial positions in the crystal with distorted octahedral or tetrahedral co-ordination

EPR Study of Fe 3+

This paper presents EPR study of Fe$\text{}^{3+}$ in triglycine sulphate doped with Fe$\text{}^{3+}$ crystal. Fe$\text{}^{3 +}$ ion is in a high spin state S=5/2. EPR signal can be detected only below 200 K. At 4.2 K the EPR spectrum results from three non-equivalent sites of Fe$\text{}^{3+}$ ions. The spin Hamiltonian: H=β BĝS+D[S$\text{}_{z}^{2}$-(1/3)S(S+1)]+E(S$\text{}_{x}^{2}$-S$\text{}_{y}^{2}$) has been applied to describe the spectrum. The zero field splitting parameter in this case fulfills the condition: D≫hν. An experimental spectrum reflects clearly only two resonance transitions: |±1/2ã (the lowest Kramers doublet) and |±3/2〉 (the middle Kramers doublet). The iron complexes occupy interstitial positions in the crystal with distorted octahedral or tetrahedral co-ordination

COEXISTENCE OF PARAELECTRIC/PROTON-GLASS AND FERROELECTRIC (ANTIFERROELECTRIC) ORDERS IN Rb_{1-x}(NH_{4})_{x}H_{2}AsO_{4} CRYSTALS

This paper reviews the results of dielectric studies of the proton glass state in a mixed crystal Rubidium Ammonium Dihydrogen Arsenate (RADA) The coexistence of paraelectric/proton glass and ferroelectric or antiferroelectric orders, confirmed by other studies, has been discussed in detail. The phase diagram of RADA is asymmetric. The proton glass state exists for ammonium concentration in the range of 0.1 < x < 0.5 . The phase diagram of deuterated DRADA is presented. The proton glass state region in DRADA, 0.2 < x < 0.35 is narrower than that for non-deuterated RADA. The effects of hydrostatic pressure on the dielectric properties in the proton glass state are presented. The glass temperature Tg decreases with pressure and is expected to vanish at 5 kbar. Low temperature behaviour is still an open question, since there is no experimental evidence of Tg(p) dependence below 4K for proton glass systems.Ця стаття є оглядом результатів діелектричного вивчення стану протонного скла у змішаних кристалах Rb₁₋x(NH₄)xH₂AsO₄ (RADA).Співіснування впорядкувань параелектричного/протонне скло та сегнетоелектричного чи антисегнетоелектричного, підтверджене іншими дослідженнями, детально обговорюється. Фазова діаграма RADA є асиметричною. Стан протонного скла існує для концентрації аміаку в межах 0, 1 < x < 0, 5 . Представлена фазова діаграма дейтерованого DRADA. Область стану протонного скла в DRADA (0, 2 < x < 0, 35) є вужчою, ніж у недейтерованому RADA. Представлені ефекти впливу гідростатичного тиску на діелектричні властивості кристалу в стані протонного скла. Температура склування Tg спадає з тиском і за оцінками прямує до нуля при 5 кбар. Низькотемпературна поведінка є все ще дискусійною, оскільки немає експериментально підтвердженої Tg(p) залежності нижче 4 К для систем протонного скла

Dielectric Study of Pressure Induced fcc-sc Phase Transition in Fullerene C60\text{}_{60}

Phase transition in polycrystalline fullerene C$\text{}_{60}$ from fcc phase to a simple cubic phase sc induced by hydrostatic pressure up to 0.5GPa was studied by dielectric method. Pressure coefficient dT$\text{}_{c}$/dp=144±8 K/GPa was determined. This value is consistent with pressure coefficients obtained with other experimental techniques

Recycling for multilayer polymer materials for use in motor vehicles

W artykule przedstawiono problemy recyklingu wyrobów z wielowarstwowych materiałów polimerowych stosowanych w pojazdach samochodowych. Analizowano możliwości rozdrabniania i segregacji poszczególnych materiałów oraz kierunki ich wykorzystania Przedstawiono recykling wyrobu z kompozytu WPC -PP (polipropylenu) modyfikowanego włóknem drzewnym.This paper presents recycling problems of products with multilayer polymeric materials used in vehicles. We analyzed the possibility of shredding and separation of individual materials and directions for their use presents a composite product recycling WPC-PP(polypropylene) modified wood fiber

Superconductivity of MgB2MgB_2 Layers Prepared on Silicon Substrate by Implantation of Magnesium Ions into Boron Substrate

The results of investigation of the $MgB_2$ layers prepared on silicon substrate by implantation of Mg ions into boron substrate are presented. After implantation the annealing processes were carried out at temperatures 673 K, 773 K, and 873 K in a furnace in an atmosphere of flowing Ar-4%$H_2$ gas mixture. The samples were characterized by: four-probe electric conductivity measurements and magnetically modulated microwave absorption. Our results showed that due to silicon substrate the diffusion of implanted Mg ions into boron materials should be limited, and the superconducting phase forms a continuous $MgB_2$ layer and the resistivity for all samples fall down to zero below $T_{c}$. The transition temperature $T_{c}$ becomes higher with increasing annealing temperature: $T_{c}$=18 K (for annealing at $T_{A}$=673 K), $T_{c}$=20 K (for annealing at $T_{A}$=773 K), and $T_{c}$=27 K (for annealing at $T_{A}$=873 K)

Dielectric Properties of K1−x\text{}_{1-x}(NH4\text{}_{4})x\text{}_{x}H2\text{}_{2}PO4\text{}_{4} (x= 0.095) Crystal

Temperature dependences of the dielectric permittivity were studied for the ferroelectric K$\text{}_{1-x}$(NH$\text{}_{4}$)$\text{}_{x}$H$\text{}_{2}$PO$\text{}_{4}$ mixed crystal. The experiments revealed presence of the beginning of the dipolar glass - embryos in the concentration of ammonium x=0.095. Observations of the dielectric relaxations show much bigger effect domain mechanism than the one related to the growth of clusters of the dipolar glass