V. V. Eremenko, S. S. Saxena, V. A. Sirenko, K. A. Minakova
Four decades since the concept of polyamorphism was introduced by [L. S. Palatnik (1909–1994), Fiz. Nizk. Temp. 25, 400 (1909)], numerous investigations proved its presence in a broad variety of nonmagnetic short-range ordered materials, like structural, metallic, a-metallic, inorganic molecule, orientational, electron glasses, water, ice, carbons, and others. It was manifested by phase transitions between amorphous states as a function of the quench condition and under compression, mediated by long-wave fluctuations of an order parameter. There has been much recent discussion given to the phenomenon of polyamorphism where distinct, different states of amorphous liquids and solids are observed as a function of density. The outstanding contribution of the recently late [A. Sella, et al. (1956–2022), Nat. Mater. 21, 490 (2022)],2 in the field should be recognized here. Underlying this phenomenon is the possibility of a first-order liquid-liquid phase transition driven by the density and entropy differences between the two amorphous phases. Magnetic boost of multilayer graphene under pressure was also recently discovered. Their famous spin counterparts, such as spin liquid, spin ice, and spin glass have been less studied at this end despite numerous similarities, registered so far. Taking that in mind, for further polyamorphism platform development, we demonstrate the signatures of phase transition in spin glass, driven by a magnetic field, and eventually, a novel type of polyamorphism, the spin-glass one.
自 L. S. Palatnik (1909-1994)，Fiz. Nizk. Temp. 25, 400 (1909)]提出多态性概念以来的四十年间，大量研究证明了多态性存在于各种非磁性短程有序材料中，如结构材料、金属材料、a-金属材料、无机分子材料、定向材料、电子玻璃、水、冰、碳等。它表现为非晶态之间的相变，是淬火条件和压缩条件的函数，由有序参数的长波波动介导。最近，人们对多态性现象进行了大量讨论，在多态性现象中，可以观察到非晶态液体和固体的不同状态与密度的函数关系。在此，我们应该承认最近去世的 A. Sella 等人 (1956-2022) [Nat. Mater. 21, 490 (2022)]2在这一领域做出的杰出贡献。这一现象的基础是两种非晶相之间的密度和熵差驱动的一阶液相转变的可能性。最近还发现了多层石墨烯在压力下的磁助推效应。尽管自旋液体、自旋冰和自旋玻璃有许多相似之处，但迄今为止对它们的研究还较少。有鉴于此，为了进一步开发多态性平台，我们展示了自旋玻璃在磁场驱动下的相变特征，并最终发现了一种新型多态性--自旋玻璃。
{"title":"Polyamorphism gets a magnetic boost","authors":"V. V. Eremenko, S. S. Saxena, V. A. Sirenko, K. A. Minakova","doi":"10.1063/10.0026269","DOIUrl":"https://doi.org/10.1063/10.0026269","url":null,"abstract":"Four decades since the concept of polyamorphism was introduced by [L. S. Palatnik (1909–1994), Fiz. Nizk. Temp. 25, 400 (1909)], numerous investigations proved its presence in a broad variety of nonmagnetic short-range ordered materials, like structural, metallic, a-metallic, inorganic molecule, orientational, electron glasses, water, ice, carbons, and others. It was manifested by phase transitions between amorphous states as a function of the quench condition and under compression, mediated by long-wave fluctuations of an order parameter. There has been much recent discussion given to the phenomenon of polyamorphism where distinct, different states of amorphous liquids and solids are observed as a function of density. The outstanding contribution of the recently late [A. Sella, et al. (1956–2022), Nat. Mater. 21, 490 (2022)],2 in the field should be recognized here. Underlying this phenomenon is the possibility of a first-order liquid-liquid phase transition driven by the density and entropy differences between the two amorphous phases. Magnetic boost of multilayer graphene under pressure was also recently discovered. Their famous spin counterparts, such as spin liquid, spin ice, and spin glass have been less studied at this end despite numerous similarities, registered so far. Taking that in mind, for further polyamorphism platform development, we demonstrate the signatures of phase transition in spin glass, driven by a magnetic field, and eventually, a novel type of polyamorphism, the spin-glass one.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"57 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The nonlinear integral equations for the components of the order parameter of dense superfluid neutron matter (SNM) with spin-triplet anisotropic p-wave pairing (similar to pairing in 3He−A2 in magnetic fields, i.e., with spin S = 1 and orbital moment L = 1 of anisotropic Cooper pairs of neutrons) in superstrong magnetic fields (exceeding the 1017 G) are solved analytically in the limit of zero temperature. These solutions are derived for the family of so-called BSk-type generalized parameterizations of the effective Skyrme forces (with three terms dependent on density n) in neutron matter. The obtained general solutions for splitting of energy gap in SNM in superstrong magnetic fields are specified for the generalized BSk21 parameterization of the effective Skyrme forces at nuclear density n0 = 0.17 fm–3 and at two supranuclear densities n = 1.25n0 and n = 1.5n0 for magnetic fields H = Z⋅1017 G, where 1≤ Z ≤ 10. The main results are the splitting of energy gap and its asymmetry which increase nonlinearly with growing both superstrong magnetic field H and supranuclear density n > n0. Such effects in SNM might exist in liquid outer core (at densities n>∼n0) in strongly magnetized neutron stars known as “magnetars”.
超强磁场（超过 1017 G）中具有自旋-三重各向异性 p 波配对（类似于磁场中 3He-A2 的配对，即各向异性库珀中子对的自旋 S = 1 和轨道力矩 L = 1）的致密超流体中子物质（SNM）的阶次参数分量的非线性积分方程在零温度极限下得到了解析求解。这些解法是针对中子物质中有效斯凯尔姆力的所谓 BSk 型广义参数化系列（三个项取决于密度 n）得出的。针对核密度 n0 = 0.17 fm-3 和两个超核密度 n = 1.25n0 和 n = 1.5n0，磁场 H = Z⋅1017 G（其中 1≤ Z ≤ 10）下有效斯凯尔姆力的广义 BSk21 参数化，给出了超强磁场下中子物质能隙分裂的一般解。主要结果是能隙的分裂及其不对称性随着超强磁场 H 和超核密度 n > n0 的增长而非线性增加。SNM 中的这种效应可能存在于被称为 "磁星 "的强磁化中子星的液态外核（密度 n>∼n0）中。
{"title":"About splitting of energy gap in superfluid neutron matter with spin-triplet anisotropic p-wave pairing at nuclear and supranuclear densities in superstrong magnetic fields","authors":"A. N. Tarasov","doi":"10.1063/10.0026245","DOIUrl":"https://doi.org/10.1063/10.0026245","url":null,"abstract":"The nonlinear integral equations for the components of the order parameter of dense superfluid neutron matter (SNM) with spin-triplet anisotropic p-wave pairing (similar to pairing in 3He−A2 in magnetic fields, i.e., with spin S = 1 and orbital moment L = 1 of anisotropic Cooper pairs of neutrons) in superstrong magnetic fields (exceeding the 1017 G) are solved analytically in the limit of zero temperature. These solutions are derived for the family of so-called BSk-type generalized parameterizations of the effective Skyrme forces (with three terms dependent on density n) in neutron matter. The obtained general solutions for splitting of energy gap in SNM in superstrong magnetic fields are specified for the generalized BSk21 parameterization of the effective Skyrme forces at nuclear density n0 = 0.17 fm–3 and at two supranuclear densities n = 1.25n0 and n = 1.5n0 for magnetic fields H = Z⋅1017 G, where 1≤ Z ≤ 10. The main results are the splitting of energy gap and its asymmetry which increase nonlinearly with growing both superstrong magnetic field H and supranuclear density n > n0. Such effects in SNM might exist in liquid outer core (at densities n>∼n0) in strongly magnetized neutron stars known as “magnetars”.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"46 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Assel Istlyaup, Lyudmila Myasnikova, Daulet Sergeyev, Marina Konuhova, Anatoli I. Popov
Modern solid-state physics increasingly focuses on the study of nanomaterials and the development of nanotechnologies. Various theoretical methods and research technologies are actively used to elucidate the significance of experimental results related to the study of solid-state defects. Progress in this field is likely associated with advancements in computer technologies and the development of modern quantum-chemical packages. The obtained spectra reveal a certain number of energy levels in the energy range from –30 to 20 eV. We determine the band structure, density of states, and total energy of NaF nanotubes with parameters (m, n), where m = 4, 5, 6, 8, and n = 1, 2, 3. The characteristics modeling is conducted using the Atomistix ToolKit software package and Virtual NanoLab program. This work presents the results of computer modeling of the density of states and total energy of NaF nanotubes within the framework of density functional theory. The obtained results allow classifying the tubular structures of NaF as quantum dots and contribute to further research into alkali metal halide crystals in nanostructures.
{"title":"Computer simulation of the density of states and band structure of NaF nanotubes","authors":"Assel Istlyaup, Lyudmila Myasnikova, Daulet Sergeyev, Marina Konuhova, Anatoli I. Popov","doi":"10.1063/10.0026283","DOIUrl":"https://doi.org/10.1063/10.0026283","url":null,"abstract":"Modern solid-state physics increasingly focuses on the study of nanomaterials and the development of nanotechnologies. Various theoretical methods and research technologies are actively used to elucidate the significance of experimental results related to the study of solid-state defects. Progress in this field is likely associated with advancements in computer technologies and the development of modern quantum-chemical packages. The obtained spectra reveal a certain number of energy levels in the energy range from –30 to 20 eV. We determine the band structure, density of states, and total energy of NaF nanotubes with parameters (m, n), where m = 4, 5, 6, 8, and n = 1, 2, 3. The characteristics modeling is conducted using the Atomistix ToolKit software package and Virtual NanoLab program. This work presents the results of computer modeling of the density of states and total energy of NaF nanotubes within the framework of density functional theory. The obtained results allow classifying the tubular structures of NaF as quantum dots and contribute to further research into alkali metal halide crystals in nanostructures.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"84 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. A. Pryshko, I. S. Novosad, Z. O. Kohut, V. M. Salapak, O. M. Horina
The temperature changes of the relative elongation (Δl/l0)i and refractive indices ni(T) of rubidium sulfate crystals in the region of low temperatures are investigated in the work. The linear dimensions and volume of the crystal decrease with a decrease in temperature, and the parameters (Δl/l0)i are anisotropic. The values of ni increase with decreasing temperature for all crystal physical directions, and the intersection of the curves nz(T) and nx(Т) at a temperature of Т = 85 K occurs. This indicates the existence of an optical isotropic point in this crystal, which is confirmed by independent temperature measurements of the angle between the optical axes. It is shown that rubidium sulfate crystals are optically biaxial, with the angle between the optical axes equal 2 V = 41.5° at room temperature. With decreasing temperature, it decreases almost linearly, so that at Т = 85 K the crystal changes from optically biaxial to optically uniaxial (2 V = 0°). The temperature changes of the values of electronic polarizability αi were calculated. It was shown that αi increases slightly as temperature decrease, so that in the region where the optical isotropic point exists, the values αх and αz are equal to each other.
该作品研究了硫酸铷晶体在低温区域的相对伸长率 (Δl/l0)i 和折射率 ni(T) 的温度变化。晶体的线性尺寸和体积随着温度的降低而减小，参数 (Δl/l0)i 是各向异性的。在所有晶体物理方向上，ni 的值都随着温度的降低而增加，并且在温度 Т = 85 K 时出现了 nz(T) 和 nx(Т) 曲线的交点。这表明该晶体中存在一个光学各向同性点，光轴之间角度的独立温度测量也证实了这一点。研究表明，硫酸铷晶体具有光学双轴性，在室温下，光轴之间的夹角等于 2 V = 41.5°。随着温度的降低，它几乎呈线性减小，因此在 Т = 85 K 时，晶体从光学双轴变为光学单轴（2 V = 0°）。计算了电子极化率 αi 值的温度变化。结果表明，随着温度的降低，αi 会略微增加，因此在存在光学各向同性点的区域，αх 和 αz 的值相等。
{"title":"Dilatometric and refractive parameters of rubidium sulfate crystals at low temperatures","authors":"I. A. Pryshko, I. S. Novosad, Z. O. Kohut, V. M. Salapak, O. M. Horina","doi":"10.1063/10.0026324","DOIUrl":"https://doi.org/10.1063/10.0026324","url":null,"abstract":"The temperature changes of the relative elongation (Δl/l0)i and refractive indices ni(T) of rubidium sulfate crystals in the region of low temperatures are investigated in the work. The linear dimensions and volume of the crystal decrease with a decrease in temperature, and the parameters (Δl/l0)i are anisotropic. The values of ni increase with decreasing temperature for all crystal physical directions, and the intersection of the curves nz(T) and nx(Т) at a temperature of Т = 85 K occurs. This indicates the existence of an optical isotropic point in this crystal, which is confirmed by independent temperature measurements of the angle between the optical axes. It is shown that rubidium sulfate crystals are optically biaxial, with the angle between the optical axes equal 2 V = 41.5° at room temperature. With decreasing temperature, it decreases almost linearly, so that at Т = 85 K the crystal changes from optically biaxial to optically uniaxial (2 V = 0°). The temperature changes of the values of electronic polarizability αi were calculated. It was shown that αi increases slightly as temperature decrease, so that in the region where the optical isotropic point exists, the values αх and αz are equal to each other.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"338 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742018","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The ground state of the spin-1/2 Ising–Heisenberg distorted diamond chain in the presence of an external magnetic field is investigated in the case of the ferromagnetic Ising and antiferromagnetic XXZ Heisenberg interactions, that exhibits a geometric frustration of spins. The influence of the quantum fluctuations, the magnetic field, and the distortion on the ground state are studied in detail. It is established that the zero-temperature magnetization curve may show intermediate plateaus at zero and one-third of the saturation magnetization.
{"title":"Ground state of the spin-1/2 Ising–Heisenberg distorted diamond chain with ferromagnetic Ising and antiferromagnetic Heisenberg interactions","authors":"B. M. Lisnyi","doi":"10.1063/10.0026258","DOIUrl":"https://doi.org/10.1063/10.0026258","url":null,"abstract":"The ground state of the spin-1/2 Ising–Heisenberg distorted diamond chain in the presence of an external magnetic field is investigated in the case of the ferromagnetic Ising and antiferromagnetic XXZ Heisenberg interactions, that exhibits a geometric frustration of spins. The influence of the quantum fluctuations, the magnetic field, and the distortion on the ground state are studied in detail. It is established that the zero-temperature magnetization curve may show intermediate plateaus at zero and one-third of the saturation magnetization.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"32 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. V. Terekhov, K. Rogacki, V. M. Yarovyi, Z. D. Kovalyuk, E. Lähderanta, E. V. Khristenko, A. L. Solovjov
The temperature dependences of the electrical resistance of the solid solution of Bi88.08Mn11.92 in the temperature range of 2–300 K and magnetic fields up to 90 kOe for both H ⊥ I and H || I are studied. It has been shown that in a magnetic field, the temperature dependences of the electrical resistance of Bi88.08Mn11.92 show maxima (insulator–metal transition) for both the H ⊥ I and H || I orientations. The temperatures of the maxima increase with increasing field. The appearance of a noticeable difference between the temperature dependences of the electrical resistances of Bi88.08Mn11.92 and the compound Bi95.69Mn3.69Fe0.62 with a lower Mn content and pure Bi is discussed. It has been established that the magnetoresistance of Bi88.08Mn11.92 is positive over the entire temperature range studied and reaches a value of 3290% in a magnetic field of 90 kOe for H ⊥ I, which is approximately 400% higher than in the Bi95.69Mn3.69Fe0.62 compound with lower Mn content. A suggestion has been made that the peculiarities temperature dependences behavior of the electrical resistance of Bi88.08Mn11.92 without a magnetic field and in the field, are largely due to the influence of internal magnetism of the α-BiMn phase and can be explained within the framework of the multiband theory.
研究了 Bi88.08Mn11.92 固溶体在 2-300 K 温度范围和高达 90 kOe 的磁场中 H ⊥ I 和 H || I 的电阻温度相关性。研究表明，在磁场中，Bi88.08Mn11.92 的电阻温度依赖性在 H ⊥ I 和 H || I 方向上都显示出最大值（绝缘体-金属转变）。最大值的温度随磁场的增加而升高。讨论了 Bi88.08Mn11.92 和锰含量较低的化合物 Bi95.69Mn3.69Fe0.62 与纯 Bi 的电阻温度依赖性之间出现的明显差异。研究发现，Bi88.08Mn11.92 的磁阻在整个研究温度范围内均为正值，在 H ⊥ I 的 90 kOe 磁场中达到 3290%，比 Mn 含量较低的 Bi95.69Mn3.69Fe0.62 化合物高出约 400%。有一种观点认为，Bi88.08Mn11.92 在无磁场和有磁场情况下的电阻随温度变化的特性，主要是由于 α-BiMn 相的内部磁性的影响，可以在多波段理论的框架内加以解释。
{"title":"Features of temperature dependences electrical resistance of Bi88.08Mn11.92 in magnetic fields","authors":"A. V. Terekhov, K. Rogacki, V. M. Yarovyi, Z. D. Kovalyuk, E. Lähderanta, E. V. Khristenko, A. L. Solovjov","doi":"10.1063/10.0026270","DOIUrl":"https://doi.org/10.1063/10.0026270","url":null,"abstract":"The temperature dependences of the electrical resistance of the solid solution of Bi88.08Mn11.92 in the temperature range of 2–300 K and magnetic fields up to 90 kOe for both H ⊥ I and H || I are studied. It has been shown that in a magnetic field, the temperature dependences of the electrical resistance of Bi88.08Mn11.92 show maxima (insulator–metal transition) for both the H ⊥ I and H || I orientations. The temperatures of the maxima increase with increasing field. The appearance of a noticeable difference between the temperature dependences of the electrical resistances of Bi88.08Mn11.92 and the compound Bi95.69Mn3.69Fe0.62 with a lower Mn content and pure Bi is discussed. It has been established that the magnetoresistance of Bi88.08Mn11.92 is positive over the entire temperature range studied and reaches a value of 3290% in a magnetic field of 90 kOe for H ⊥ I, which is approximately 400% higher than in the Bi95.69Mn3.69Fe0.62 compound with lower Mn content. A suggestion has been made that the peculiarities temperature dependences behavior of the electrical resistance of Bi88.08Mn11.92 without a magnetic field and in the field, are largely due to the influence of internal magnetism of the α-BiMn phase and can be explained within the framework of the multiband theory.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"38 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We have performed Raman studies of a LiNiPO4 single crystal at temperatures below and above the phase transition to a magnetically ordered state at 5 and 25 K, respectively. A shift of some phonon lines during the transition to a magnetically ordered state was observed that is explained by a significant spin-phonon interaction. We identified the anomalous Raman lines using the shell-model calculation. It was found that with an increase in temperature, some external vibrational modes shift to the low-frequency region, and the internal vibrational modes of the (PO4)3– tetrahedra shift to the high-frequency region. This anomalous behavior of the vibrational modes is explained by the presence of magnetostriction that can selectively act on the bonds between ions in the crystal upon the transition to a magnetically ordered state.
我们分别在低于和高于磁有序态相变温度（5 K 和 25 K）的情况下对锂镍磷酸盐单晶体进行了拉曼研究。在向磁有序态转变的过程中，我们观察到一些声子线发生了偏移，这可以用明显的自旋-声子相互作用来解释。我们利用壳模型计算确定了异常拉曼线。研究发现，随着温度的升高，一些外部振动模式向低频区转移，而 (PO4)3- 四面体的内部振动模式则向高频区转移。振动模式的这种反常行为可以用磁致伸缩来解释，在过渡到磁有序状态时，磁致伸缩会选择性地作用于晶体中离子之间的键。
{"title":"Computational and spectroscopic comparative analysis of Raman phonon spectra of LiNiPO4","authors":"A. V. Peschanskii, A. Yu. Glamazda","doi":"10.1063/10.0026325","DOIUrl":"https://doi.org/10.1063/10.0026325","url":null,"abstract":"We have performed Raman studies of a LiNiPO4 single crystal at temperatures below and above the phase transition to a magnetically ordered state at 5 and 25 K, respectively. A shift of some phonon lines during the transition to a magnetically ordered state was observed that is explained by a significant spin-phonon interaction. We identified the anomalous Raman lines using the shell-model calculation. It was found that with an increase in temperature, some external vibrational modes shift to the low-frequency region, and the internal vibrational modes of the (PO4)3– tetrahedra shift to the high-frequency region. This anomalous behavior of the vibrational modes is explained by the presence of magnetostriction that can selectively act on the bonds between ions in the crystal upon the transition to a magnetically ordered state.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"43 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. P. Nerubatskyi, E. S. Hevorkian, R. V. Vovk, Z. Krzysiak, H. L. Komarova
The paper analyzes the effect of nanoadditives of zirconium dioxide, partially stabilized by Y2O3, on the Al2O3–SiO2 matrix during hot pressing by the electroconsolidation method. The microstructure obtained at different compositions and sintering modes is studied. It was established that the introduction of nanopowder ZrO2–3 mol % Y2O3 increases the crack resistance of sintered samples not only due to the transformation of the tetragonal phase to the monoclinic phase, but also due to the formation of a solid solution with aluminum oxide at the interphase boundaries. Starting from a temperature of 1400 °C, complete densification occurs with the formation of nonporous composites while preserving the nanostructure. At this temperature, the formation of mullite with cristobalite phases also begins. The high value of thermocycles makes it possible to use this composite material as a cryogenic one. The fabrication of mullite-corundum composites with additions of ZrO2–3 mol % Y2O3 nanopowders via the method of electrosolidification has enabled the attainment of high fracture toughness, K1C = 14.5 MPa⋅m1/2, and hardness HV10 = 14 GPa. These results evidence excellent mechanical properties, thereby expanding the potential applications of this material.
{"title":"The influence of zirconium dioxide nanoadditives on the properties of mullite-corundum","authors":"V. P. Nerubatskyi, E. S. Hevorkian, R. V. Vovk, Z. Krzysiak, H. L. Komarova","doi":"10.1063/10.0026282","DOIUrl":"https://doi.org/10.1063/10.0026282","url":null,"abstract":"The paper analyzes the effect of nanoadditives of zirconium dioxide, partially stabilized by Y2O3, on the Al2O3–SiO2 matrix during hot pressing by the electroconsolidation method. The microstructure obtained at different compositions and sintering modes is studied. It was established that the introduction of nanopowder ZrO2–3 mol % Y2O3 increases the crack resistance of sintered samples not only due to the transformation of the tetragonal phase to the monoclinic phase, but also due to the formation of a solid solution with aluminum oxide at the interphase boundaries. Starting from a temperature of 1400 °C, complete densification occurs with the formation of nonporous composites while preserving the nanostructure. At this temperature, the formation of mullite with cristobalite phases also begins. The high value of thermocycles makes it possible to use this composite material as a cryogenic one. The fabrication of mullite-corundum composites with additions of ZrO2–3 mol % Y2O3 nanopowders via the method of electrosolidification has enabled the attainment of high fracture toughness, K1C = 14.5 MPa⋅m1/2, and hardness HV10 = 14 GPa. These results evidence excellent mechanical properties, thereby expanding the potential applications of this material.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"46 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The long-term goal of our study is to perform a simulation on a rapidly rotating gas of ultracold bosonic atoms. When the rotation frequency is close to the harmonic trap frequency, the trapping force is compensated by the centrifugal force and only the Coriolis force remains, analogous to the Lorentz force. The quantum Hall effect regime is reached when the number of vortices is larger than the number of atoms. In this work, we demonstrate a variety of excitations of the fractional quantum Hall states of composite fermions and ultracold two-dimensional rapidly rotating bosonic atoms. Second, we can also check directly whether there is a relationship between these two phenomena by calculating the energy of N = 8 bosons in the ground state of the harmonic oscillator and a few-boson elementary excitations for the Bose–Laughlin state at the half filling factor.
我们研究的长期目标是对快速旋转的超冷玻色原子气体进行模拟。当旋转频率接近谐波阱频率时，阱力被离心力补偿，只剩下科里奥利力，类似于洛伦兹力。当漩涡数量大于原子数量时，量子霍尔效应机制就会出现。在这项工作中，我们展示了复合费米子和超冷二维快速旋转玻色原子的分数量子霍尔态的各种激发。其次，我们还可以通过计算谐振子基态中 N = 8 玻色子的能量和玻色-劳克林态在半填充因子下的少数玻色子基本激发，直接检验这两种现象之间是否存在关系。
{"title":"Fractional quantum Hall effect of a rapidly rotating gas of ultracold bosonic atoms","authors":"M. Ahmed Ammar, S. Boucherf","doi":"10.1063/10.0026246","DOIUrl":"https://doi.org/10.1063/10.0026246","url":null,"abstract":"The long-term goal of our study is to perform a simulation on a rapidly rotating gas of ultracold bosonic atoms. When the rotation frequency is close to the harmonic trap frequency, the trapping force is compensated by the centrifugal force and only the Coriolis force remains, analogous to the Lorentz force. The quantum Hall effect regime is reached when the number of vortices is larger than the number of atoms. In this work, we demonstrate a variety of excitations of the fractional quantum Hall states of composite fermions and ultracold two-dimensional rapidly rotating bosonic atoms. Second, we can also check directly whether there is a relationship between these two phenomena by calculating the energy of N = 8 bosons in the ground state of the harmonic oscillator and a few-boson elementary excitations for the Bose–Laughlin state at the half filling factor.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"30 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
For one of the famous and widely investigated intermediate valence compound YbB12, the experimental studies of the pressure effect on magnetic susceptibility χ(P) were carried out under helium gas pressure P up to 2 kbar at fixed temperatures 78 and 300 K using a pendulum type magnetometer. The measurements show a slight increase in susceptibility under pressure, which is consistent in sign with similar literature data for other ytterbium compounds with intermediate valence of Yb ions. Based on a model analysis of experimental data, the pressure derivative of Yb valence in YbB12 was estimated for the first time, the value of which is in line with the general trend of the valence behavior under pressure in rare earth compounds exhibiting intermediate valence.
对于一种著名的、被广泛研究的中间价化合物 YbB12，在氦气压力 P 高达 2 千巴、温度固定为 78 和 300 K 的条件下，使用摆锤式磁力计对压力对磁感应强度 χ(P) 的影响进行了实验研究。测量结果表明，在压力作用下，磁感应强度略有增加，这与其他具有中间价镱离子的镱化合物的类似文献数据一致。根据对实验数据的模型分析，首次估算出了 YbB12 中镱价的压力导数，其值符合稀土化合物在压力下表现出中间价的一般趋势。
{"title":"Magnetic properties of YbB12. Pressure effects","authors":"A. S. Panfilov, A. A. Lyogenkaya, G. E. Grechnev","doi":"10.1063/10.0026247","DOIUrl":"https://doi.org/10.1063/10.0026247","url":null,"abstract":"For one of the famous and widely investigated intermediate valence compound YbB12, the experimental studies of the pressure effect on magnetic susceptibility χ(P) were carried out under helium gas pressure P up to 2 kbar at fixed temperatures 78 and 300 K using a pendulum type magnetometer. The measurements show a slight increase in susceptibility under pressure, which is consistent in sign with similar literature data for other ytterbium compounds with intermediate valence of Yb ions. Based on a model analysis of experimental data, the pressure derivative of Yb valence in YbB12 was estimated for the first time, the value of which is in line with the general trend of the valence behavior under pressure in rare earth compounds exhibiting intermediate valence.","PeriodicalId":18077,"journal":{"name":"Low Temperature Physics","volume":"30 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141742019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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