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(1-x)H3BO3-xPE (x = 0.0–0.5) microwave dielectric polymer-ceramics (composite ceramics) with ultra-low sintering temperatures (60–110 °C) were prepared via the traditional solid-state method to improve the moisture-proof ability of H3BO3 matrix ceramics. X-ray diffraction (XRD), back-scattered scanning electron microscopy (EDS-SEM), and Raman spectroscopy confirmed that H3BO3 and PE could coexist without intermediate phases. As the x value increased, the dielectric Q value and resonant frequency (Q × ƒ) decreased from 116,000 GHz (at 15.0 GHz) to 37,000 GHz (at 16.3 GHz), the relative permittivity (er) varied between 2.83 and 2.14, and the temperature coefficient of the resonant frequency (τƒ) shifted from −147 ppm/°C to +27 ppm/°C in the (1-x)H3BO3-xPE (0.0 ≤ x ≤ 0.5) microwave ceramics at their optimal sintering temperatures. A near-zero τƒ value (+9 ppm/°C) was obtained in the 0.7H3BO3-0.3 PE composite, which simultaneously exhibited an er value of ~2.38 and a Q × ƒ value of ~46,000 GHz (at 15.7 GHz) after sintering at 100 °C for 1 h. Interestingly, through the hydrolysis experiment (24–384 h), the Q × ƒ values of the 0.7H3BO3-0.3 PE and/or 0.6H3BO3-0.4 PE polymer-ceramics were basically maintained at approximately 35,000–40,000 GHz. These results showed that the novel (1-x)H3BO3-xPE polymer-ceramics should be the potential candidates for ultra-low temperature co-fired ceramic (ULTCC) technology.

(1–x)NdGaO3-xBi0.5Na0.5TiO3 [(1–x)NdGaO3-xBNT, 0.05 ≤ x ≤ 0.7)] ceramic systems were fabricated using a conventional solid-state reaction, and their phase structures, microstructures, and microwave dielectric characteristics were systematically investigated. The XRD patterns results showed an orthorhombic perovskite structure as the main phase with a Pbnm space group at x = 0.05. In a range of x = 0.1–0.3, the main Nd3Ga5O12 cubic structure phases (Ia-3d space group) had been formed due to the increase in the cation vacancies resulting from the Na and Bi ion volatilization at the higher densification sintering temperatures (1400–1450 °C). As (Na0.5Bi0.5)2+ ions increased and the sintering temperatures decreased, the orthorhombic perovskite-type Pnma space group solid solutions (the main phases) were detected at x = 0.4 and 0.5, accompanied with a certain amount of second phase Bi2O3 in the samples at x = 0.6 and 0.7. The results of Raman spectroscopy analysis, EDS data analysis, and surface morphologies observations were basically in keeping well with the XRD analysis results, wherein the Raman-active modes also implied that the crystal structure of the main phase actually had a tendency to change the perovskite structure when x = 0.3. The er value increased gradually as the x value increased from 0.05 to 0.5 because of the increase in the ionic polarizability, and increased slowly at x = 0.6, then decreased slightly as the x value further increased to 0.7 due to the formation of the second phase. The Q × f values of the (1-x)NdGaO3-xBNT (x = 0.05–0.7) ceramic systems were strongly influenced by the densification, lattice defects, and phase composition and content. The τf values could be well predicted by replacing Na, Bi and Ti ions with suitable substitutions for these ceramic systems. As a result, the new temperature-stable ceramics with optimal dielectric properties of er ~43.1, Q × f ~6700 GHz (at 5.85 GHz), and τf ~ −24.5 ppm/°C and er ~ 44.5, Q × f ~ 5600 GHz (6.12 GHz), and τf ~ +2.4 ppm/°C were obtained in the (1-x)NdGaO3-xBNT composite series at x = 0.5 and x = 0.6 sintered at 1320 °C and 1250 °C for 4 h, respectively.

Eleven novel NNN Cu(II) complexes supported by a tridentate bis(imidazo[1,2-α]pyridin-2-yl)pyridine ligand were synthesized and characterized by elemental analysis, HRMS, and X-ray determination. Target prediction and docking studies indicated that these pincer complexes formed hydrogen bonds with Asp33 and Gly35 of Cathepsin D protein, which is highly associated with prognosis of advanced prostate cancer. Furthermore, they exhibited anti-proliferation activity in both androgen-sensitive and androgen-insensitive prostate cancer cells according to WST-1 assay results. Mechanistic study showed that pincer complexes arrested cell cycle progression at G0/G1 phase and inhibited Cathepsin D regulated signaling pathways. Most importantly, new pincer copper complexes significantly inhibited xenograft prostate cancer growth along with a promising in vivo safety profile. In summary, these results suggest the applicability of the developed novel pincer copper complexes as promising anticancer agents for prostate cancer treatment.

Ultrahigh dielectric constant (er) (1-x-y)Bi0.5Na0.5TiO3-xLi0.5Sm0.5TiO3-yNa0.5La0.5TiO3 (BNT-LST-NLT, 0.3 ≤ x ≤ 0.7, 0.0 ≤ y ≤ 0.4) microwave ceramic systems were fabricated using a conventional solid-state reaction method, and their phase structures, microstructures, and microwave dielectric characteristics were systematically investigated. From XRD pattern analyses and refinement results, (1-x-y)BNT-xLST-yNLT (x = 0.3–0.6 and y = 0.4–0.1) samples were crystallized into a cubic perovskite structure, and XRD peaks corresponding to the (031), (131), and (230) planes were identified as super-reflections belonging to the tilt system of orthorhombic a−a−b+ with the Pnma space group. In particular, on the basis of the Raman spectra and microwave dielectric properties analysis results, the crystal structure of the sample (x = 0.6 and y = 0.1) sintered at 1200 °C for 4 h was considered to be closer to orthorhombic symmetry. In addition, solid orthorhombic perovskite-type solutions were formed together with a small amount of secondary phase Sm2Ti2O7 as x = 0.6 and y = 0.2, 0.3. However, an increase in the Sm2Ti2O7 phase content was also detected for x = 0.7 and y = 0.0, accompanied by the perovskite phase. For the microwave dielectric properties, the er and Q×f values strongly depended on the apparent density, ionic polarizability, phase structure, and phase composition, and also, the τf value was predicted by adjusting the tolerance factor (t). The er and τf values basically agreed with the existing models, such as the mixing rule. As a result, the (1-x-y)BNT-xLST-yNLT (x = 0.6 and y = 0.1) ceramic sample sintered at 1200 °C for 4 h exhibited superior microwave dielectric properties of er ~ 149.1, Q×f ~ 3270 GHz, and τf ~ 39.1 ppm/°C.

Negative temperature coefficient (NTC) thermistor thin films based on perovskite-type BaBiO3 (BB) and BaZn0.06Bi0.94O3-δ (BZB) were successfully prepared by radio frequency (RF) magnetron sputtering method on Pt substrate. The crystal structure and grain morphology of the BZB and BB films deposited at different substrate temperatures (25–200 °C and 200 °C, respectively) were examined by X-ray diffraction (XRD) and atomic force microscope (AFM). The substrate temperature had a significant influence on the crystallinity and phase structure, in which the main crystalline phases with the cubic and tetragonal BaBiO3-based perovskite structures could be obtained on the substrate temperatures of 100 °C and 200 °C, respectively. On the other hand, the electrical properties were analyzed by measuring the resistance temperature (ρ-T) characteristics, and all the thin films exhibited good NTC thermistor characteristics. In addition, the grain (Rg) and grain boundary (Rgb) contribution to the total resistance were estimated by three parallel R-CPE equivalent circuits in series, in which the main contribution of resistance for BZB thin film deposited at 200 °C was derived from Rg response rather than that in Rgb at the higher temperature range. This was one of the most important reasons why this sample had a good NTC behavior, and this result was confirmed by the current-voltage (I-V) characteristics analysis. For the BB film, the room-temperature resistivity (ρ25) was 1540 Ω cm (B25/85 –3240 K), while the ρ25 value decreased to approximately 1156 Ω cm (B25/85 –3183 K) for BZB film deposited at a same substrate temperature (200 °C). This is mainly due to the change in crystal structural characteristics. It is believed that the substitution of Zn2+ for BB thin films deposited at an appropriate temperature will be useful for low-resistance applications as novel thin film NTC thermistors.

Sm2O3-Nd2O3-MgO-CeO2 ceramic systems of the form Sm1-xNdx(Mg0.5Ce0.5)O3 (0.0 ≤ x ≤ 1.0) were synthesized by a conventional solid-state reaction method, and the phase structural characteristics, microstructures, sintering behaviors and microwave dielectric properties were investigated systematically. X-ray diffraction analyses revealed that a cubic fluorite-type structure with Fm-3m (225) space group was identified as the main crystalline phase in the composition range of x = 0.0–1.0, while some secondary phases were also detected in all the Sm1-xNdx(Mg0.5Ce0.5)O3 samples. The phase structural characteristics of Sm2O3-Nd2O3-MgO-CeO2 quaternary ceramic systems were significantly affected by a certain amount of Mg2+ ion volatilization, detected by the typical EDS data. Additionally, both an example of EDS analysis in the second phases regions and some details of the diffraction peaks implied that the unknown phases were mainly composed of MgO phase. Furthermore, for the microwave characteristics, the relative permittivity (er) was closely related to the dense degree and phase compositions, and also, the quality factor (Q × f) had been strongly depended on the compactness and lattice defects in these investigated ceramics. Wherein, after sintering at 1450 °C for 4 h, the x = 0.0 sample demonstrated the excellent microwave dielectric performance: er ∼16.6, Q × f ∼111,280 GHz (at 7.938 GHz) and τf ∼ −56.7 ppm/°C. These results also indicated that the Ce1-xLnxO2-δ (Ln = Sm and Nd) solid solutions could be a good candidate for dielectric resonators, filters and other microwave electronic device applications.

Glass-ceramics with a mass fraction composition (wt%) of 19MgO-23Al2O3-53SiO2-4TiO2-xV2O5 (x = 2.5, 3 and 3.5, abbreviated as samples V2.5, V3 and V3.5) were prepared by two-step heat treatment of the parent glass at selected nucleation and crystallization temperatures for different holding time (2 h and 20 h), respectively. The effects of V2O5 on crystalline phases, microstructures and microwave dielectric properties of the glass-ceramics were investigated in detail. X-ray diffraction (XRD) analyses revealed that the main phases could be identified as α-cordierite and SiO2 phases, and also some amount of μ-cordierite phase and a trace of Al2Si4O10, Mg(VO4)2 and TiO2 phases were also detected in all these glass-ceramics' XRD patterns. In addition, an appropriate V2O5 addition with 3.0–3.5 wt% was found to cause an increase in the content of the precipitated crystalline phases. Based on the EDM observation, a fraction of Ti4 + and V5 + ions were remained in the residual glass matrix of the crystallized specimens. Additionally, the microwave dielectric properties were closely depended on not only the different two-step heat treatment temperatures and holding time, but also the relative densities and degree of crystallization of the glass matrix. Wherein, the fully densified V3 glass-ceramic sample heat-treated at 850 °C/2 h + 950 °C/20 h exhibited a lower dielectric constant (er) of ~ 3.79, a higher quality factor (Q × f) of about 12,520 GHz (at 13.693 GHz) and a near-zero temperature coefficient of resonant frequency (τf) of ~ − 5.4 ppm/°C, which provided a promising candidate for LTCC applications.

Based on the formula of BaBi0·92Cu0·08O3, Cu-modified Ba–Bi–O-based perovskite-like negative temperature coefficient (NTC) thermistor thin films were successfully prepared by radio frequency (RF) magnetron sputtering method with the various deposition temperatures (25 °C, 100 °C, 200 °C and 250 °C). The effects of the substrate temperatures on the phase structures and electrical properties were respectively characterized and investigated by X-ray diffraction (XRD), resistance-temperature measurement, and complex impedance analysis for the Ba–Bi–O-based thin films. Additionally, the cross-sectional microstructures and grain morphologies of the BaBi0·92Cu0·08O3 thin films were analyzed by scanning electron microscope (SEM) and atomic force microscope (AFM). The XRD patterns results showed that the perovskite monoclinic structure with a small amount of BaBiO2.5 s phase could be obtained for the BaBiO3 thin film deposited at 200 °C, and also, the main crystalline phase was transferred from BaBiO2.82 to BaBiO2.5 when the BaBi0·92Cu0·08O3 thin films were deposited at 200 °C and 250 °C, respectively. Temperature dependent complex impedance spectroscopy was carried out to make clear the resistance contribution of grain (Rg), grain boundary (Rgb) and contact (Rs) response for the conduction mechanisms in the Ba–Bi–O-based thin film deposited at a given substrate temperature. Compared with the electrical properties of the BaBiO3 thin film deposited at 200 °C [such as the room-temperature resistivity (ρ25 ~ 1548 Ω cm) and the thermistor constant (B25/85–3245 K)], the better NTC characteristics of a lower ρ25 value of about 956 Ω cm and a higher B value of approximately 3480 K were found in the BaBi0·92Cu0·08O3 thin film deposited at a same temperature (200 °C). It is believed that the phase structures and electrical properties of the BaBiO3 perovskite-type NTC thermistor thin films could be adjusted and optimized by a trace amounts of Cu-ions substitutions and depositing at an appropriate substrate temperature, which also showed that such as these novel BaBiO3-based thin films are feasible with the extensive of actual applications for the NTC thermistors.