Dielectric Diffusion Research Articles

Mass transport mechanism of nitrate selective nanofiltration membranes on the basis of the Donnan steric pore model with dielectric exclusion (DSPM-DE)

Nanofiltration (NF) membranes can play an important role to mitigate the nitrate pollution, emphasizing the necessity for understanding its mass transport mechanism to enhance water purification strategies. This study focuses on the nitrate separation capabilities of thin film composite NF membranes having a polyamide (PA) selective layer. The selective layer of the membranes was fabricated through interfacial polymerization, with varying piperazine (PIP) and trimesoyl chloride (TMC) monomer concentrations on porous polyacrylonitrile substrates. We studied their retention on aqueous solutions of PEG 200, single salts (NaCl, NaNO3, Na2SO4), and mixed salts (NaCl + NaNO3 and NaNO3 + Na2SO4). Through a new fitting scheme, the Donnan Steric Pore Model with Dielectric Exclusion (DSPM-DE) was utilized to correlate the PIP and TMC concentrations with the ion transport and exclusion mechanisms responsible for the membranes’ nitrate separation capabilities. The model could simulate the Na+/NO3-/SO42- system but not Na+/NO3-/Cl-. Dielectric exclusion and diffusion were the dominant partitioning and transport mechanisms, respectively, explaining the high retentions of sulfate (96 to 99 %) and the negative retentions of nitrate (−24 to 11 %). This study sheds light on the potential of NF membranes having PA selective layers for efficient nitrate/sulfate separation, providing valuable insights into the underlying transport and exclusion mechanisms.

Effect of Pr3+ doping on relaxation behavior and strain response of PHT-based piezoelectric ceramics

Heterovalent ion doping has influenced the further development of piezoelectric applications. Pr3+ doping in relaxor ferroelectrics is rarely focused on piezoelectric performance enhancement. 0.51 Pb(Ni1/3Nb2/3)O3-0.49 Pb(Hf0.3Ti0.7)O3 (PNN-49PHT) ceramics with Pr3+ doping ceramics were designed and fabricated by a two-step precursor method. Excellent dielectric diffusion coefficient (γ) of 1.96 was achieved at the low Pr3+ doping concentration of 0.2 %. Increased relaxation enhanced the nanoscale domains formation, resulting in a giant strain response (d*33) of 1400 pm/V at 10 kV/cm, and a total strain (Stol) of 0.27 % at 20 kV/cm. Structural refinement unveiled that the high piezoelectricity originated from the mainly substitution of Pr3+ for Pb2+ at the A-site, inducing lattice distortion and phase transitions. Local domain switching and long-range ordered destruction were investigated by piezoresponse force microscopy (PFM) and Scanning Electron Microscopy (SEM). These findings contribute to the advancement of piezoelectric devices and provide valuable insights for the design and optimization of high-performance piezoelectric ceramics.

Observation of Micro-Scale Domain Structure Evolution under Electric Bias in Relaxor-Based PIN-PMN-PT Single Crystals

Relaxor ferroelectrics play a vital role as functional components in electromechanical devices. The observation of micro-scale domain structure evolution under electric bias in relaxor ferroelectrics has posed challenges due to their complex domain morphology characterized by small-sized domains. The present study aims to investigate the dielectric diffusion–relaxation characteristics, domain structure, and domain switching evolution under electric bias in high-performance single crystals of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-33PbTiO3. The findings reveal the presence of strip-like domain patterns that interlock irregular small-sized nanodomains in PIN-PMN-33PT single crystals. Furthermore, the sample undergoes three distinct stages under electric bias, including the nucleation of new domains, the gradual forward expansion of domains, and the lateral expansion of domains. These observations provide valuable insights for understanding and exploring domain engineering techniques in relaxor ferroelectrics.

The unexpected diffuse phase transition in relaxor-PbTiO3 ferroelectrics via acceptor modification

The diffuse phase transition (DPT) and domain structure are essential to the functional properties of relaxor ferroelectrics and are extremely sensitive to the ion doping. The utilization of acceptor doping has been observed to be an effective method in enhancing the high-power properties of relaxor ferroelectric materials. The present study aims to examine the acceptor-doped DPT and domain structure in single crystals of Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3. An unexpected physical phenomenon was identified in which Mn-doping increased dielectric diffusion and lowered domain size while suppressing dielectric relaxation. Traceability investigations suggest that Mn-doping inhibited the growth of polar nanoregions by enhancing random electric fields, which increases dielectric diffusion while decreasing the domain size. Meanwhile, Mn doping redistributes the relaxation time function, which results in a reduction in dielectric relaxation. The current research deepens the understanding of the physical basis of DPT and can be applied to the development of high-performance piezoelectric materials.

Unique electric and dielectric features of dipole-pair substituted barium titanate ferroelectric ceramics (I): electrical characterization

A comparison study of pure barium titanate BaTiO3, dipole-pair [Ga3+, Ta5+] substituted barium titanate Ba(Ga3+, Ta5+)0.005Ti0.99O3 ([Ga3+, Ta5+]: BaTiO3), single ion [Ga3+] substituted barium titanate Ba(Ga3+)0.01Ti0.99O3 ([Ga3+]: BaTiO3), and single ion [Ta5+] substituted barium titanate Ba(Ta5+)0.01Ti0.99O3 ([Ta5+]: BaTiO3) ferroelectric ceramics have been conducted in order to discern the unique electric and dielectric properties derived from dipole-pair substitution. The band gap, DC resistivity, relative permittivity, dissipation factor, and complex impedance have been measured and analyzed. The dipole-pair substituted material is demonstrated to be an excellent dielectric, which possesses high electrical resistivity, high activation energy, significant dielectric diffuseness, high relative permittivity and low dissipation factor, due to charge compensation and creation of dipole-pairs in barium titanate solid solution ceramic matrix. The single substituted (acceptor and donor, respectively) samples behave more like traditional semiconductors, which have lower electrical resistivity, lower activation energy, and exhibit strong dielectric anomaly and large dissipation factor due to charge imbalance (electrons and holes) in part compensated for through additional defect creation. The relaxor-like behavior of the dipole-pair substituted sample is distinguishable from the classic relaxor through electric properties and structural phase diagram and is anticipated to spark more attention and further exploration. The unique features of electric resistivity and dielectric diffuseness of the dipolar-pair engineered BaTiO3 affords opportunity for designing properties of novel relaxor-like ferroelectrics.

Structure, dielectric, and ferroelectric properties of (1-x)Bi0.5Na0.5TiO3 – X K0.5Na0.5NbO3 (0 ≤ x ≤ 0.1) solid solution

The correlation of the phase structure, dielectric, and ferroelectric properties of lead-free (1-x)(Na0.5Bi0.5)TiO3–xK0.5Na0.5NbO3 (NBTKNx) (0 = x ≤ 0.1) polycrystalline ceramics, fabricated via a solid state reaction technique, were investigated. The Rietveld refinement allowed identifying the crystallographic transformation from a rhombohedral to a coexisting rhombohedral-tetragonal or tetragonal long range-ordered ferroelectric (FE) phase. The dielectric investigations showed an increase of the dielectric diffuseness (1.53 = γ ≤ 1.73) and a clear shift of the depolarization temperature (Td) to a lower temperature while increasing substitution. More importantly, the lattice disorder also generated a plateau-like dielectric anomaly, leading to a thermally stable ϵr ∼2859 ± 20% (120–500 °C) and ∼3112 ± 10% (120–420 °C) for x = 0.075 and 0.1 samples, respectively. At room temperature (RT), Raman spectroscopy investigations revealed a downshift of the frequencies as a function of the composition with an inhomogeneous broadening of the Raman lines. On heating, Raman spectra showed changes in the region where the dielectric transitions are observed. Moreover, the composition dependence of the current peaks in the I-E loops confirmed the occurrence of a phase transition from a non-ergodic polar phase to an ergodic weakly polar after the applying of an electric field of 60 kV/cm−1.

Induced Chemical Networking of Organometallic Tin in a Cyclic Framework for Sub-10 nm Patterning and Interconnect Application

Given the need for advanced resist materials in view of fast shrinkage of semiconductor node scaling, this work demonstrates the lithography application of an organotin-based cyclotrimeric species (Sn–CT) as a molecular resist for sub-10 nm patterning using electron beam lithography (EBL) and helium ion beam lithography (HIBL) techniques. While the resist has been successfully used for patterning ∼15 nm line/space features and ∼9 nm discrete line features at a dose of 2.5 mC/cm2 using EBL, ∼15 nm line/space features were printed on silicon at a dose of 16 μC/cm2 using HIBL. Moreover, Sn–CT has also been used for patterning complex features at a single nanometer regime such as real-scale device designs at ∼7 nm structure on silicon. A mechanistic study using X-ray photoelectron spectroscopy (XPS) revealed the formation of Sn–O–Sn and Sn–OH networks along with the loss of carbon-based group(s) upon radiation exposure, resulting in the generation of insoluble products in the exposed region, which becomes the basis of polarity switching and hence pattern development. The resist was found to have good etch resistance with respect to silicon. Moreover, Sn–CT has been explored as a good gap-filling material for silicon (Si) front-end devices and interconnects due to its low-κ dielectric (∼1.9) and high diffusion barrier properties.

The microstructure and dielectric properties of Yb2O3 doped 0.92BaTiO3 - 0.08(Na0.5Bi0.5)TiO3 relaxor ceramics

The dielectric properties and mechanism of xYb2O3 doped 0.92BaTiO3 - 0.08(Na0.5Bi0.5)TiO3 ceramics with x = 0.005–0.025 have been investigated. The addition of 0.015 mol Yb2O3 improves the permittivity and enhance diffuseness of temperature dependent permittivity for 0.92BaTiO3 - 0.08(Na0.5Bi0.5)TiO3, which gives an εr′ variation within ±10 % in 20–170 °C. Core-shell microstructures observed in the grains of samples, which is responsible for the dielectric diffuseness and permittivity of xYb2O3 doped 0.92BaTiO3 - 0.08(Na0.5Bi0.5)TiO3 ceramics. Three different relaxation responses are identified by the impedance analysis as grain boundary, grain shell and grain core responses from the low to high frequency. The Yb2O3 shows neglectable effect to the grain boundary but affects the grain shell and grain core obviously. The Yb3+ are mainly in grain shells as x < 0.015 and distributed both in the grain shell and core region as x ≥ 0.015.

Relaxor multiferroic properties of nanostructured BaTiO3–Fe2O3–Bi2O3 lead free for energy storage applications

Relaxor multiferroic properties of nanostructured 0.30BaTiO3–0.52Bi2O3–0.18Fe2O3 mol% (BFBT) were prepared via the mechanical activation method. The mixed powders were ball milled at 10, 20, 30, 50 and 75 h to obtain nanostructured materials. Room temperature XRD patterns for these nanostructured materials at different ball-milling times were investigated. The ball milled of nanostructured BFBT at different ball-milling times is characterized and identified by FTIR. After 50 h, HRTEM revealed the nanostructure of BFBT with an average particle size of 27.86 nm. Dielectric characterization showed a broad and frequency-dependent diffusion in phase transition around 560 K that shifted to the higher temperature with increasing frequency. The dielectric diffusivity (Υ = 1.78) was calculated from the modified Curie–Weiss law. Dielectric permitivitty (ε′) data were fitted using the Vogel–Fulcher relation, confirming the relaxor nature. Furthermore, the slim P-E hysteresis loop demonstrates recoverable energy density (Wrec = 16.17 mJ/cm3) and energy storage efficiency (η = 89.3%) at 360 K. The Néel Temperature (TN = 394 K) was determined by the magnetic susceptibility measurements. The M-H date shows a weak ferromagnetic behavior of the 50 h mechanical milled sample. Therefore, the presented work provides guidelines for synthesizing nanostructured BFBT by mechanical milling for the development of high-potential lead-free energy storage applications.

Domain structure and dielectric diffusion-relaxation characteristics of ternary Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 ceramics

Relaxor-based ternary Pb([Formula: see text][Formula: see text])O3–Pb([Formula: see text][Formula: see text])O3–PbTiO3 (PIN–PMN–PT) single crystals and ceramics are promising candidates for high-performance electromechanical conversion devices. It is known that the domain structure and dielectric diffusion–relaxation characteristics are crucial to the excellent performances of relaxor ferroelectrics. In this work, we prepared the PIN–PMN–PT ceramics with various PIN/PMN proportions and systematically investigated their domain structure and dielectric diffusion–relaxation properties. The effect of PIN/PMN proportion on the domain size and dielectric diffusion–relaxation characteristics was also studied. The investigations showed that PIN–PMN–PT ceramics presented multi-type domain patterns comprising irregular island domains and regular lamellar domains. Moreover, the dependent relations of PIN/PMN proportions on the dielectric diffusion and domain size indicated that the PIN composition has a stronger lattice distortion than PMN composition; increasing the PIN proportion can enhance the dielectric diffusion and decrease the domain size. Our results could deepen the understanding of structure–property relationships of multicomponent relaxor ferroelectrics and guide the design and exploration of new high-performance ferroelectric materials.

Correlations between electrocaloric effect and dielectric diffuseness of lead-free Ba(Ti1-Sn )O3 ceramics

This paper reported the correlations between electrocaloric effect (ECE) and dielectric diffuseness of Ba(Ti1-xSnx)O3 (abbreviated as BT-100xSn) ceramics. The BT-100xSn with pure perovskite structure has been synthesized by conventional solid-state reaction method. The temperature dependence of dielectric permittivity indicates that all the BT-100xSn ceramics are normal ferroelectric with diffused phase transition, and the dielectric diffuseness is strengthened as the Sn contents increase. The maximum ECE takes place in the vicinity of phase transition point, which is the characteristic of normal ferroelectrics. The BT-8Sn indicates the largest ∆T = 0.46 K and ∆T/∆E = 0.30 × 10−6 K m/V. The substitutions of Sn contents adjust the maximum ECE to different temperatures, and the good temperature-modulation of ECE is beneficial for the realization of ECE application. Considering the correlations between ECE and dielectric diffuseness, the experimental results demonstrate that the stronger dielectric diffuseness leads to the strengthened temperature stabilities of ECE but accompanied with decreased maximum ECE.

Influence of Ester Liquids on Dielectric Strength of Cellulose Kraft Paper

Generally, impregnation of solid insulation is performed to increase the dielectric strength and reduce the dielectric losses of solid insulants. This increase in dielectric strength depends on the oil’s diffusion and dielectric properties. This paper investigates the diffusion behavior of mineral oil and ester fluids (synthetic, natural, and mixed) to understand the influence of oil diffusion on paper breakdown voltage. To better understand this phenomenal influence, cellulose insulation paper of different thicknesses has been considered. Wetting characteristics of various oil-paper insulation systems were investigated with and without thermal stressing. Thermal aging was carried out as per modified ASTM D1934 at 110 °C, 140 °C, 160 °C, and 185 °C respectively for 2 weeks. The wetting characteristics and influence of different oils on paper breakdown voltage were explicitly reported. It is inferred that paper wetting characteristics are attributable to the type of oil, the thickness of paper, and the aging factor of oil-paper insulation. Importantly, the increase in paper dielectric strength and diffusion behavior for ester fluids is found to be superior to that of the mineral insulating oils.

Separation of succinic acid from fermentation broth: Dielectric exclusion, Donnan effect and diffusion as the most influential mass transfer mechanisms

Nanofiltration can be used to separate succinic acid (SA) from other organic acids in a fermentation broth. However, commercial nanofiltration membranes can be insufficiently selective since some produced organic acids have similar molecular weights. SA production from biomass fermentation entails separation of succinic acid from the other concomitantly produced organic acids such as acetic acid, formic acid, pyruvic acid etc. In this study, five commercial nanofiltration membranes were tested for SA rejection and selectivity under dead-end and crossflow modes of SA recovery from selected synthetic solutions and a real fermentation broth. SA rejections up to 94.1 ± 1.5% and 95.5 ± 3.5% were observed for the synthetic broth and the fermentation broth, respectively. The SA fractions obtained in the retentate were nearly 70% and 60% for synthetic and fermentation broth, respectively. The highest rejections and SA fraction values were achieved with DK and NF270 membranes, which also showed the highest permeate flux. Model evaluation using the Donnan-steric pore model with dielectric exclusion (DSPM-DE) showed that 99% of the SA rejection occurs at the membrane interface and not inside the membrane. Based on the modelling, the most important mechanism affecting separation was dielectric exclusion at both sides of the membrane surfaces. Moreover, identified sensitive model parameters, i.e. pore dielectric constant (εpore), charge density (Xd) and pore radius (rp), were estimated through model fitting and were found to be highly correlated with significant variations. Finally, for the first time, a calibrated model with synthetic broth was successfully used to predict organic acids rejection for a real fermentation broth (with 12% and 3% prediction error for succinate rejection by NF270 and DK, respectively). Such prediction was achieved only by measuring organic acid concentrations in the fermentation broth and using the three sensitive parameters. Furthermore, the potential contribution of different transport mechanisms of SA was quantified for the first time.

Augmentation of the reverse electrodialysis power generation in soft nanochannels via tailoring the soft layer properties

Nanochannels covered with a polyelectrolyte layer (PEL) are recently shown to increase the power generation by reverse electrodialysis (RED) considerably. In this investigation, we numerically study the influences of the electrolyte-PEL property difference on the RED energy conversion in conical-shaped nanochannels covered with dense polyelectrolyte layers. The current-voltage aspects of the nanochannel are determined through solving the Poisson-Nernst-Planck and the Navier-Stokes-Brinkman equations for steady-state conditions while taking into account different values of the dielectric permittivity, diffusion coefficient, and viscosity for the electrolyte and the PEL. The results indicate a relatively high sensitivity of the maximum energy conversion efficiency and the maximum power generated to the PEL-electrolyte property difference, especially at moderate and high values of the high-to-low concentration ratio. This implies that the RED power generation characteristics may be effectively controlled via tailoring the PEL structure. More specifically, both the efficiency and the maximum rate of power generation may be increased by densely distributing the polyelectrolyte brushes. For example, a power density of 75W.m−2 can be obtained by using a dense PEL with the thickness 5nm, a value that is impossible to achieve even with thicker PELs when the properties of the electrolyte and PEL are the same.

High dielectric tunability with high thermal stability of the (111) highly oriented 0.85Pb(Mg1/3Nb2/3)-0.15PbTiO3 thin film prepared by a sol-gel method

Ferroelectric thin films with high tunability, low dielectric loss, high figure-of-merit (FOM) and high thermal stability are attractive to military and civil tunable devices such as phase shifters, filters, etc. In this work, the (100), (110) and (111) highly oriented 0.85Pb(Mg1/3Nb2/3)-0.15PbTiO3 (PMN-15PT) relaxor ferroelectric thin films were prepared by a sol-gel method. The (111) highly oriented PMN-15PT thin film has high dielectric tunability (η) value of ∼ 80% at 1500 kV/cm, high thermal stability (±2% variation) from room temperature to ∼ 450 K and the dielectric tunability is independent from 500 Hz to 10 kHz. The high dielectric tunability of the (111) highly oriented PMN-15PT thin film is associated to the reorientation of polar nanoregions (PNRs) and intrinsic lattice phonon polarization. Meanwhile, the excellent thermal stability may be attributed to the large dielectric diffuseness degree (γ ∼ 1.81) derived from the modified Curie-Weiss law. It is believed that the (111) highly oriented PMN-15PT thin film is an attractive material in the application of the next-generation tunable devices.

Ti-doping induced antiferroelectric to ferroelectric phase transition and electrical properties in Sm-PbZrO3 thin films

The antiferroelectric (Pb0.985Sm0.01) (Zr1-xTix)O3 (Ti-PSZO) thin films were synthesized on Pt(111)/Ti/SiO2/Si substrates using a chemical solution deposition method. The films were crystallized in the perovskite phase with a preferential orientation along (111) direction. With Ti doping in PSZO, a gradual transformation from antiferroelectric to ferroelectric phase transition was noticed at room temperature owing to the Ti doping induced lattice distortion. The phase transition has been confirmed through the P - E hysteresis loops, X-ray diffraction (peak shifting), capacitance-voltage measurements, and Raman scattering analysis. The thin film with Ti = 0.15 doping displayed a ferroelectric behavior with high dielectric constant and large dielectric tunability of about 62%. Also, Ti doping altered the Curie temperature (Tc) and enhanced the order of dielectric diffuseness. It is believed that Ti-doping in PSZO is an effective way to induce an antiferroelectric - ferroelectric phase transition and to tailor the electrical characteristics of PSZO thin films.

Growth of Thin Graphite Films on a Dielectric Substrate using Heteroepitaxial Synthesis

A technique for growing thin graphite films on a dielectric substrate by annealing the Al2O3(0001)/Ni(111)/ta-C structure has been optimized. This technique is based on catalytic decomposition of hydrocarbons on the surface of a single-crystal catalyst metal film on a dielectric substrate and subsequent diffusion and crystallization of carbon between the metal film and the substrate. A thin graphite film with a low density of crystal-structure defects is obtained on the dielectric substrate after chemical etching of the metal film.

The influence of structure evolution on dielectric performance in BaZr0.1Ti0.89Fe0.01O3 ceramics

BaZr0.1Ti0.89Fe0.01O3 ceramics sintered at 1240–1340 °C were prepared by solid-state method. The sample underwent phase transition from rhombohedral to orthorhombic phase, which changed the internal stress. Increasing the sintering temperature promoted grain growth (from 0.44 to 1.87 μm). The dielectric constant (e = 4300) and diffusion coefficient (γ = 1.927) of the sample were improved significantly. The improvement mechanism of dielectric constant and dispersion phase transition was explained by the internal stress model and 90° domain structure in detail.

Effects of vacancy defects caused by non-stoichiometric ratio on dielectric properties of ABO3 perovskite (Ba0.5Sr0.5)xTiO3 ceramics

Non-stoichiometric Ba0.5Sr0.5TiO3 (BST50) ceramics with varying A/B ratios, namely (Ba + Sr)/Ti, were prepared by a conventional solid-state reaction approach. The effects of vacancy defects caused by varying the A/B ratio on the structure and dielectric properties of BST50 ceramics were systematically investigated. A remarkable change in grain size was found when the A/B ratio was increased, which led to apparent variations in the dielectric properties of the BST50 ceramics. The Curie temperature (Tc) and dielectric permittivity peak (εmax) increased first and then decreased with increasing A/B ratio, and reached the maximum at A/B = 1. Simultaneously, the dielectric diffusion parameter of BST50 ceramics was studied by the Lorenz-type formula. All samples exhibited diffusion phase transition behavior, and Tc was frequency independence. When A/B < 1, the Q value remained at a high level; in contrast, when A/B > 1, the Q value was significantly reduced. For this BST50 system, high tunability of 24.95% (at 30 kV/cm), low dielectric loss of 0.0017 (at 10 kHz), and high figure of merit (FOM) of 147 were achieved simultaneously at A/B = 1.01.

39 Nanowater enhances cryoprotective effects of glycerol during ram semen freezing

It was suggested that unique physicochemical properties of nanowater (NW, water declustered in the cold plasma generator), such as a low dielectric constant and high diffusivity, might ameliorate ram semen freezing by improving bioavailability of extender constituents. This study was undertaken to evaluate the effects of NW added to glycerol-containing semen extenders on the characteristics of frozen-thawed ram semen. A total of 18 ejaculates collected from 6 Olkuska breed rams during the breeding season were divided into six equal portions. The ejaculates were frozen in the modified fructose-skimmed milk-egg yolk Kareta extender containing 3 or 7% glycerol and diluted in deionized water (control extenders; Aqua Purificata, Prolab; C3% and C7%, respectively) or NW (declustered for 15min (NW15’) or 30min (NW30’); Nanotechnology Systems) to a final concentration of 800×106 spermatozoa/mL. They were placed in 0.25-mL plastic straws and frozen in liquid nitrogen. The two declusterization times were chosen on the basis of previous laboratory tests and fertility trials yielding the best results in terms of semen quality post-thawing and pregnancy rates after AI. All semen samples were evaluated for sperm concentration, progressive motility (Sperm Class Analyzer), and morphological defect rates (Nikon Eclipse 80i microscope, Nikon Corp.). In addition, the ex situ survival time at 37°C and extender content of alanine transferase, alkaline phosphatase, and aspartate aminotransferase were measured, along with the proportions of apoptotic, necrotic, and live spermatozoa determined post-thawing with flow cytometry (BD Accuri™ C6 Plus, Becton Dickinson) at 0 and 1h post-thawing. Data were analysed by one-way analysis of variance and Holm-Sidak method using SigmaPlot statistical software (Systat Software Inc.). The proportion of spermatozoa with mid-piece defects was significantly (P&amp;lt;0.05) reduced in NW15’-3% compared with C3% (1.3±0.3% vs. 4.0±06%; mean±s.e.m.). The proportion of necrotic spermatozoa 1h after thawing was greater (P&amp;lt;0.05) in C7% compared with NW30’-7% (20.7±0.4% vs. 17.6±1.0%), whereas the proportions of live cells detected immediately (0h) and 1h after thawing were greater (P&amp;lt;0.05) in NW30’-7% than in C30’ (0 h: 54.0±0.6% vs. 50.4±1.2%; 1 h: 54.4±1.2% vs. 59.2±0.4%, respectively). The mean survival time of spermatozoa was greater (P&amp;lt;0.05) in extenders dissolved in NW30’compared with their respective controls (NW30’-3% vs. C3%: 215±4min vs. 189±6 min; and NW30’-7% vs. C7%: 242±8min vs. 217±4min, respectively). Alkaline phosphatase concentrations in extenders prepared with NW30’ were lower (P&amp;lt;0.05) compared with the control groups (NW30’-3% vs. C3%: 3105±231IU vs. 4490±458 IU; and NW30’-7% vs. C7%: 2516±128IU vs. 3956±263IU, respectively). Our results indicate that NW significantly improves the effects of glycerol on ram sperm viability post-thawing, with the reduction in sperm necrosis/overall enhancement of sperm survivability being greater with 7% compared with 3% of glycerol in semen extender.