Search

We investigated the effect of magnetic coupling (the energy constant of unit area: Jcpl) between CoFeB free layers on thermal stability factor Δ in Magnetic Tunnel junction (MTJ) with CoFeB/MgO double Interfacial Perpendicular Magnetic Anisotropy (IPMA). We newly introduced Jcpl in models for calculations, which were based on magnetic domain propagation model when MTJ diameter d is larger than critical diameter dc and magnetization coherent rotation model when d ≤ dc. With increasing Jcpl, Δ increases and saturates when Jcpl is over a critical value Jcpl_c. Magneto-static coupling constants (Jstat) between the free layers were also calculated. Jstat is so smaller than Jcpl_c and cannot maximize Δ by itself, that an interlayer exchange coupling (the critical energy constant of unit area: Jex_c) is required to cover the difference between Jcpl_c and Jstat. Jex_c also rapidly increases with the decrease of d and reaches a plateau of 0.15 mJ/m2 in d ≤ 30 nm. MTJ devices with a smallest Jex (=0.01 mJ/m2) and a moderate PMA (constant per unit area: Keff t*) were made and Δs were evaluated by experiments. The experimental Δs were fitted by the calculations with adjusting stiffness constants As. The calculated Δs and the experimental Δs were in good agreement when the As was a smaller value than that of the blanket film. Since the experimentally used Jex value was almost zero, Δ values were estimated when Jex was a greater value of 0.15mJ/m2. As a result, 30% enhancement of Δ was obtained at the smallest d = 20 nm.

We developed perpendicular magnetic tunneling junctions (MTJs) with four synthetic antiferromagnetically coupled Co/Pt layers (Quad-SyF) and investigated their magnetic and transport properties. The quad SyF comprised four Co/Pt layers and three 0.9 nm-thick Ru coupling layers, which consisted of Co/Co/Pta/Ru/Co/Co/Ptb/Ru/Co/Co/Ptc/Ru/Co/Co/Ptd from top to bottom. The exchange coupling field (Hex) reached a maximum of 1 T when the values of a, b, c, and d were 1, 2, 2, and 1, respectively. The tunnel magnetoresistance ratio of the MTJ with the Quad-SyF and the second-peak conventional Double-SyF increased as the annealing temperature was increased up to 400°C, whereas that of the MTJ with the first-peak conventional Double-SyF degraded at temperatures of more than 350°C in the blanket films. A 55 nm-diameter MTJ with Quad-SyF was found to be stable even against an external magnetic fields up to 300 mT. In contrast, in the conventional Double-SyF, the reference-layer magnetization direction flips at around 250 mT. The shift magnetic field of the MTJ with Quad-SyF becomes approximately zero when the values of a, b, c, and d were 1, 4, 1, and 2, respectively. No back-hopping of the MTJ with Quad-SyF was observed even for the write pulse width (tW) down to 10 ns. In contrast, an MTJ with conventional Double-SyF exhibited back-hopping. In the patterned MTJ with conventional Double-SyF, as the MTJ size decreases, the coercive field of Co/Pt significantly increases and Hex decreases, causing the m-H curve of the reference layer to cross the zero magnetic field. This enables both parallel and antiparallel configurations for the top and bottom Co/Pt layers in Double-SyF at the zero magnetic field, which could induce back-hopping. However, the m-H curves of the reference layer in the patterned MTJ with Quad-SyF are far from the zero magnetic field owing to the high Hex and low Hc, which could lead to the suppression of back-hopping.

Background: A significant increase in the incidence of papillary thyroid carcinoma (PTC) in subjects exposed to radiation at a young age is a well-documented health consequence of the Chernobyl accident. The ongoing Thyroid Ultrasound Examination (TUE) program in children and adolescents of Fukushima Prefecture in Japan also indicated a high prevalence of PTC although its attribution to radiation exposure is a subject of debate. The objective of this study was to perform histopathological analysis of tumor architecture and invasive properties in (i) radiogenic post-Chernobyl and sporadic PTCs from Ukraine, and (ii) PTCs in patients from Fukushima and other Prefectures of Japan of comparable age groups. Methods: The Ukrainian radiogenic PTCs included 245 PTCs from patients who resided in three highly 131I-contaminated regions and 165 sporadic PTCs diagnosed in residents of the same regions who were born after the accident and therefore not exposed to radioiodine. The Japanese series included 115 PTCs detected during the preliminary and the first full-scale surveys of the TUE in Fukushima and 223 PTCs from patients resident in other Prefectures. All of the subjects were included in the main statistical analysis. Three additional analyses were performed limiting the subjects to children, adolescents, and adults. Results: Ukrainian radiogenic PTC was characterized by the higher frequency of tumors with a dominant solid-trabecular growth pattern and higher invasiveness, more frequent extrathyroidal extension, lymphatic/vascular invasion, regional and distant metastases when compared with sporadic Ukrainian PTC. The integrative "invasiveness score," based on five cancer characteristics, was also higher in the radiogenic group. The differences were most pronounced in children. In contrast, no significant differences in tumor morphology or invasiveness were observed between the two Japanese groups or the three age subgroups. The only statistically significant findings were the higher proportion of male patients, smaller mean tumor size, and higher frequency of T1b tumors in the Fukushima group. Conclusions: The difference in morphological features that indicate biological behavior of PTC between the radiation-related and sporadic groups from Ukraine, together with the lack of such in the two groups from Japan, strongly suggest a nonradiogenic etiology of PTC from Fukushima and other Prefectures.

The feasibility of X nm-generation scaling with magnetic tunnel junctions (MTJs) in spintronic memory is aimed at keeping up with state-of-the-art transistor scaling. Magnetocrystalline anisotropy, shape magnetic anisotropy, and multi-interfacial magnetic anisotropy have been proposed to overcome thermal fluctuation even at the X nm-generation. The high magnetocrystalline anisotropy of the L10-ordered alloy combined with graphene as a tunneling barrier in the MTJs was the main concern in this study, and their potential for scaling for both 10 year data retention and nanosecond writing efficiency by micromagnetic simulation is investigated. Data retention of 10 years and high-speed writing of 2.2 ns are simultaneously achieved in the MTJs with a junction diameter of 7 nm.

We successfully developed 25-nm quad CoFeB/MgO-interfaces perpendicular magnetic tunnel junction (quad-MTJ) with enough thermal stability. To fabricate the quad-MTJ, a physical vapor deposition (PVD) process for depositing novel free layer and low resistance-area ( RA ) product MgO layer and low-damage fabrication processes were developed. The developed quad-MTJ technology and advanced process bring better tunnel magneto resistance (TMR) ratio and RA to quad-MTJ than those of double-interface MTJ (double-MTJ), even though quad-MTJ has an additional MgO layer. Scaling down the MTJ size to 25 nm, we demonstrated the advantages of quad-MTJ compared with double-MTJ as follows: 1) two times larger thermal stability factor ( $\Delta $ ), which results in over ten years retention; 2) superiority of large $\Delta $ in the measuring temperature range up to 200 °C; 3) ~1.5 times higher write efficiency; 4) lower write current at short write pulse regions at less than 100 ns; and e) excellent endurance of over 1011 thanks to higher write efficiency, which results from the reduced voltage owing to low RA and the low damage integration process technology. As a result, the developed quad-MTJ technologies will open the way for the realization of high-density STT-MRAM with low power, high speed, high reliability, and excellent scalability down to $2\times $ nm node.

Histological classification and cytology reporting format described in General Rules for the Description of Thyroid Cancer, the 8th edition (2019) (the Japanese General Rules) were briefly introduced. Moreover, the differences between "the Japanese General Rules", and WHO Histological Classification, the 4th edition (2017) and The Bethesda System for Reporting Thyroid Cytopathology, the 2nd edition (2018) were also explained. The Japanese General Rules did not accept the borderline lesions of thyroid tumor which were newly shown in WHO Histological Classification. We believe it is not necessary to introduce these borderline lesions in daily practice in Japan. Borderline lesions were proposed for avoiding over-surgery for thyroid cancer patients. In the United States, when the patient is diagnosed as malignant on cytology, total thyroidectomy is generally recommended. However, there is no over-surgery in Japan, because surgeons have several choices of treatment for thyroid cancer patients. This article is the first that the Japanese General Rules was shown by foreign language. Therefore, this will be advantageous to us when we present our opinion concerning histology and cytology of thyroid tumor to the world.

We fabricated a quadruple-interface perpendicular magnetic tunnel junction (MTJ) (Quad-MTJ) down to 33 nm using physical vapor-deposition, reactive ion etching, and damage-control integration process technologies that we developed under a 300-mm process. We demonstrated the greater scalability and higher writing speed of Quad-MTJ compared with double-interface perpendicular MTJ: 1) it has twice the thermal stability factor—1X nm Quad-MTJ can achieve 10 years retention—while maintaining a low resistance-area product and high tunnel magnetoresistance ratio; 2) smaller overdrive ratio of write voltage to obtain a sufficiently low write-error rate; 2) smaller pulsewidth dependence of the switching current; and 4) more than double the write efficiency at 10-ns write operation down to 33-nm MTJ. The effective suppression of the switching current increase for higher write speeds was explained by the spin-transfer-torque model using the Fokker-Planck equation. Our 33-nm Quad-MTJ also achieved excellent endurance (at least 1011) owing to its higher write efficiency and low-damage integration-process technology. It is thus a promising method for low power, high speed, and reliable STT-MRAM with excellent scalability down to the 1X nm node.

A crystallographically heterogeneous interface was fabricated by growing hexagonal graphene (Gr) using chemical vapor deposition (CVD) on a tetragonal FePd epitaxial film grown by magnetron sputtering. FePd was alternately arranged with Fe and Pd in the vertical direction, and the outermost surface atom was identified primarily as Fe rather than Pd. This means that FePd has a high degree of

Bi-doped (La,Sr)MnO3 [(Bi0.18La0.56Sr0.30) Mn0.96O3: BLSMO, tBLSMO = 63 nm] epitaxial films were grown on NaGdO3 (NGO) substrates by a flux-mediated doping approach. That is, the growth of a (La,Sr...

We investigated the influence of hard mask (HM) materials on tunnel magnetoresistance (TMR) properties and magnetic properties for the magnetic tunnel junctions with pependicular easy axis (p-MTJs) with double CoFeB/MgO interface annealed at 400 °C for 0.5–10 h. After annealing at 400 °C for 5 h, the TMR ratio of the MTJ with TiN HM was significantly decreased, whereas the TMR ratio of the MTJ with Ta-HM was maintained at a value of more than 120%. The analysis results by secondary-ion mass spectrometry (SIMS) and energy-dispersive X-ray spectroscopy (EDX) revealed that Ru in Ru-cap for the MTJ with TiN-HM diffused into the free layer through the MgO-cap layer, resulting in the degradation of the magnetic and TMR properties of the MTJ with TiN-HM. In contrast, Ru did not diffuse into the free layer for the MTJ with Ta-HM, which results from suppression of Ru diffusion into the free layer due to the formation of Ta–Ru alloy. Furthermore, in both the MTJs with TiN-HM and Ta-HM annealed at 400 °C for 10 h, EDX analysis revealed Pt diffusion into the CoFeB reference layer, which could degrade the magnetic properties of the reference layer, resulting in the degradation of TMR properties. To obtain a double CoFeB/MgO interface p-MTJ with higher thermal tolerance, it is necessary to design an HM material that suppresses the diffusion of the cap material into the free layer in addition to suppressing the Pt diffusion of the reference layer.

BACKGROUND Carcinosarcoma (spindle cell carcinoma) of the esophagus is an extremely rare event; the etiology and origins of this neoplasm have not yet been determined. Epithelial-mesenchymal transition (EMT) has been associated with invasion and metastasis, and may be related to the generation of a stem cell population within this tumor. CASE SUMMARY We present the case of a 61-year-old male with nausea and fever. Upper gastrointestinal endoscopy revealed the presence of type 1 and 0-IIc lesions located 35 cm from the incisors toward the esophago-gastric junction. Thoracoscopic esophagectomy was performed. Macroscopic analysis revealed three polypoid lesions in the abdominal esophagus that accompanied the main lesion in the lower thoracic esophagus and 0-IIc lesions that spread continuously with them. Histologically, the lesions included proliferating spindle cells. Adeno-carcinomatous components were detected in a section near the foot, and squamous cell carcinoma was identified in the mucosa at the base of the tumor. The patient was diagnosed with multiple carcinosarcomas, staged at pT1b (SM3), pN1 (#110, #7), cM0, Stage II (sarcomatous metastasis to the lymph nodes). Spindle cells did not express E-cadherin but were positive for EMT markers, including zinc finger E-box-binding homeobox 1, TWIST, and snail family transcriptional repressor 2. The patient has experienced no recurrence at 5 years and 2 mo after surgery. CONCLUSION This report suggests that multiple sarcomatous tumors may be generated from primary squamous cell carcinoma via mechanisms related to EMT.

Graphene on $L1_0$-FePd(001), which has been experimentally studied in recent years, is a heterogeneous interface with a significant lattice symmetry mismatch between the honeycomb structure of graphene and tetragonal alloy surface. In this work, we report on the density functional study of its atomic-scale configurations, electronic and magnetic properties, and adsorption mechanism, which have not been well understood in previous experimental studies. We propose various atomic-scale models, including simple nontwisted and low-strain twisted interfaces, and analyze their energetical stability by performing structural optimizations using the van der Waals interactions of both DFT-D2 and optB86b-vdW functionals. The binding energy of the most stable structure reached $E_\mathrm{B}=-0.22$~eV/atom for DFT-D2 ($E_\mathrm{B}=-0.19$~eV/atom for optB86b-vdW). The calculated FePd-graphene spacing distance was approximately 2~\AA, which successfully reproduced the experimental value. We also find out characteristic behaviors: the modulation of $\pi$-bands, the suppression of the site-dependence of adsorption energy, and the rise of \color{blue} moir\'e-like \color{black} corrugated buckling. In addition, our atomic structure is expected to help build low-cost computational models for investigating the physical properties of $L1_0$ alloys/two-dimensional interfaces., Comment: 10 pages, 11 figures

We have firstly fabricated quad-interface perpendicular MTJ (Quad-MTJ) down to 33 nm with our developed PVD, RIE and damage control integration process technologies under 300 mm process. Secondly, we demonstrated scalability merit as well as high speed writing of Quad-MTJ compared with double-interface p-MTJ (Double-MTJ) as follows; (a) two times larger thermal stability factor $\Delta(1\mathrm{X}$ nm Quad- MTJ is extrapolated to achieve 10 years retention.), (b) lower write voltage at short write pulse regions at less than 30 ns, (c) in scaled MTJ, effective suppression of write current increase for higher write speed, (d) more than 2 times higher write efficiency at 10ns write operation down to 33 nm MTJ. Finally, we revealed that our developed 33 nm Quad-MTJ achieve excellent endurance of more 1011 thanks to higher write efficiency and low damage integration process technology. These results show that the Quad-MTJ technology is one of promising way for low power, high speed and enough reliable STT -MRAM with excellent scalability down to 1X nm node.

Background Thyroid ultrasound screening for children aged 0 to 18 years was performed in Fukushima following the accident at the Fukushima Daiichi Nuclear Power Plant. As a result, many thyroid cancer cases were detected. To explore the carcinogenic mechanisms of these cancers, we analyzed their clinicopathological and genetic features. Methods We analyzed 138 cases (52 males and 86 females) who had undergone surgery between 2013 and 2016 at Fukushima Medical University Hospital. Postoperative pathological diagnosis revealed 136 (98.6%) cases of papillary thyroid cancer (PTC). Results The BRAFV600E mutation was detected using direct DNA sequencing in 96 (69.6%) of the thyroid cancer cases. In addition, oncogenic rearrangements were detected in 23 cases (16.7%). Regarding chromosomal rearrangements, 8 (5.8%) RET/PTC1, 6 (4.3%) ETV6(ex4)/NTRK3, 2 (1.4%) STRN/ALK, and 1 each of RET/PTC3, AFAP1L2/RET, PPFIBP/RET, KIAA1217/RET, ΔRFP/RET, SQSTM1/NTRK3 and TPR/NTRK1 were detected. Tumor size was smaller in the BRAFV600E mutation cases (12.8 ± 6.8 mm) than in wild-type BRAF cases (20.9 ± 10.5 mm). In the BRAFV600E mutation cases, 83 (86.5%) showed lymph node metastasis, whereas 26 (61.9%) of the wild-type BRAF cases showed lymph node metastasis. Conclusions The BRAFV600E mutation was mainly detected in residents of Fukushima, which was different from post-Chernobyl PTC cases with RET/PTC3 rearrangement. PTC with the BRAFV600E mutation was smaller but was shown in the high rate of central cervical lymph node metastasis than the wild-type BRAF PTC in the young population of Fukushima.

Magnetic tunnel junctions (MTJ) with MgO/Fe based interfaces and out-of-plane spin direction form the basis of present-day spin-transfer-torque magnetic random-access memory (STT-MRAM) devices. They are a leading type of nonvolatile memory due to their very long endurance times and lack of reliability problems. Many semiconductor devices, such as the field effect transistor or nonvolatile memories, have undergone fundamental changes in materials design as dimensional scaling has progressed. Here, we consider how the future scaling of the MTJ dimensions might affect materials choices and compare the performance of different tunnel barriers, such as 2D materials like h-BN with the existing MgO tunnel barriers. We first summarize key features of MgO-based designs of STT-MRAM. We then describe general aspects of the deposition of 2D materials and h-BN on metals. We compare the band structures of MgO and h-BN with their band gaps corrected for the GGA band error. The different absorption sites of h-BN on Fe or Co are compared in terms of physisorbtive or chemisorbtive bonding sites and how this affects their spin-polarized bands and the transmission magneto-resistance (TMR). The transmission magneto-resistance is found to be highest for the physisorptive sites. We look at how these changes would affect the overall TMR and how scaling might progress.

Spin–torque ferromagnetic resonance (ST-FMR) spectra of nano-scaled CoFeB/MgO/CoFeB full perpendicular magnetic tunnel junctions (p-MTJs) were investigated, especially in detail at low dc-bias voltage region. Usually in in-plane magnetized MTJs (i-MTJs), the ST-FMR spectrum line shape reverses its symmetry as switching dc-bias voltage polarities; however, it is found that in the p-MTJs the line shape reversal behaves differently, that not only the spectrum shows anti-symmetric line shape at zero dc bias but also the dependence of reversal symmetry on dc bias is broken. Based on the framework of homodyne-detected ST-FMR, we extracted the parameters characterizing the spectra and discussed the possible factors resulting these differences.

Revitalization of local cities is one of the major issues for Japan. The international convention can attract foreign participants to the venue and increase the local economic ripple effect. Therefore, by questionnaires investigation for the interests and expectations of participants, we clarify the needs of participants and present it to local cities / bureaus as reference for planning and developing international conference venues. The results show that respondents are interested in sightseeing local tourist sites, so local government should play an important role in making strategy for repeat visitation of foreign visitors.

We investigated the effects of surface modification treatment (SMT) on the perpendicular magnetic anisotropy (PMA) and the thermal tolerance of top-pinned magnetic tunnel junctions (MTJs) with a Co/Pt synthetic ferrimagnetic coupling reference layer. Applying an SMT to the bottom Pt layer increased the PMA of the overlying Co/Pt multilayer. X-ray diffraction spectrum analysis revealed that the SMT resulted in a higher crystallinity and smaller lattice spacing in the Co/Pt multilayer in the thinner bottom Pt layer, which may have increased the PMA in the Co/Pt multilayer. The tunnel magnetoresistance (TMR) ratio of the MTJ with SMT increased as the annealing temperature was increased up to 400 °C; conversely, the TMR ratio of the MTJ without SMT decreased at an annealing temperature of 400 °C. Evaluation of the m-H loops revealed that, after annealing at 400 °C, the reference layers in the MTJs after SMT possessed better magnetic properties than those in the MTJs without an SMT; this is attributable to the higher PMA of the reference layers with SMT. EDX line analysis revealed that SMT suppressed Pt diffusion to the MgO barrier, resulting in a higher thermal tolerance and larger PMA of the reference layer.

Magnetic coupling between two CoFeB layers through the W insertion layer is important in the conventional double CoFeB/MgO interface, magnetic tunneling junctions (MTJs) (double-MTJs) with MgO/CoFeB/W/CoFeB/MgO free layer stack because it increases the effective magnetic volume of the free layer. The magnetic coupling energy constant per unit area, Jcpl, between two CoFeB layers through the W layer and the effective perpendicular magnetic anisotropy (PMA) energy constant per unit area, Kefft*, were investigated for conventional double-MTJs with various W insertion layer thicknesses. As the W layer thickness increased, Kefft* increased and Jcpl decreased. There exists a trade-off relationship between Jcpl and Kefft*. In conventional double-MTJs with a single W insertion layer, large values for Jcpl and Kefft* were difficult to obtain simultaneously. To improve this tradeoff, we employed a free layer stack with a thin ferromagnetic layer (ferromagnetic bridge layer: FBL) located in the W insertion layer. In the double-MTJs with FBL annealed at 400 °C, a large Jcpl value of 0.37 mJ/m2 was achieved while maintaining the maximum values of Kefft*. Accordingly, the MTJ with FBL provides an MTJ stack structure for obtaining high thermal stability.

BiFeO3 epitaxial films (tBFO = 1–10 nm) were grown on a LaSrMnO3 (tLSMO = 70 nm) buffer layer and capped with a Ru or Ru/Al layer. The BiFeO3 ultrathin film (tBFO = 3 nm) was confirmed to be continuous and flat over a wide area. Piezoelectric response and switching of spontaneous polarization were observed in the ultrathin films by switching-spectroscopy piezoelectric force microscopy measurements. Using the lock-in method with a modulation frequency of 10 Hz in x-ray absorption spectroscopy (XAS), a difference was observed between the left- and right-circularly polarized XAS signals of Fe L3 and L2 owing to x-ray magnetic circular dichroism (XMCD). The number of Fe L3 and L2 XMCD peaks indicated that a mixture of oxygen octahedron and tetrahedron (divalent and trivalent) structures might be formed. The tBFO dependence of XMCD revealed that approximately 1 nm thick ferro-like magnetic properties emerged on the BiFeO3 side of the BiFeO3/Ru interface. Ru may partially extract oxygen from BiFeO3, forming an oxygen tetrahedron structure. The BiFeO3/Ru bilayer exhibits both a piezoelectric response and ferro-like magnetism, which is promising as the basic structure of multiferroic tunnel junctions.

Mn-poor LaSrMnO 3 (LSMO) epitaxial films were grown on SrTiO 3 (100) substrates by radio frequency magnetron sputtering in an argon and oxygen gas mix, and then the samples were annealed in air at various temperatures ( T a ). 2 theta-chi X-ray diffraction mapping, nano-beam diffraction analysis through transmission electron microscopy, and electron back scatter diffraction through scanning electron microscopy revealed that the crystal symmetry of the LSMO films changed from monoclinic/orthorhombic to rhombohedral on annealing in air. Curie temperature ( T C ) of the LSMO films was found to increase with increasing T a , and become higher than the room temperature at T a ≥ 861 °C, indicating that the cause of these changes was the filling of oxygen and the transition of the crystal symmetry into rhombohedral.

We investigated the tunneling magnetoresistance (TMR) properties for the magnetic sensor application in MgO-based magnetic tunnel junctions (MTJs) using a perpendicularly magnetized [Co/Pd]-based reference layer and an in-plane magnetized CoFeB sensing layer with various thicknesses ( $t_{{\mathrm{CoFeB}}}$ ). Linear TMR curves to an out-of-plane magnetic field were successfully obtained with a dynamic range of more than 600 Oe, corresponding to the coercivity of the [Co/Pd]-based reference layer. The MTJs showed the highest sensitivity of 0.026%/Oe for $t_{{\mathrm{CoFeB}}} = 1.8$ nm and the smallest nonlinearity of 0.11% full scale for $t_{\mathrm{CoFeB}} = 3$ nm. We clarified that the sensitivity and the nonlinearity in the MTJs are significantly associated with $t_{{\mathrm{CoFeB}}}$ , which is attributed to the change in the anisotropy field of the CoFeB sensing layer.

Neuroendocrine tumors of the thyroid gland are generally considered to derive from parafollicular endocrine cells (C cells) and are generally referred to as medullary thyroid carcinomas (MTC). Calcitonin secretion is almost always detected in MTC and a prerequisite for both clinical and pathological diagnosis. Thyroid neuroendocrine tumors without any apparent calcitonin secretion reflect a diagnostic dilemma because non-calcitonin-producing MTCs have virtually not been characterized. Here, we report a case of primary thyroid neuroendocrine tumors lacking calcitonin secretion or expression. The tumor cells expressed cytokeratins, chromogranin A, and synaptophysin, all of which were consistent with epithelial and neuroendocrine differentiation. Thyroid transcription factor-1 paired box gene 8, and carcinoembryonic antigen were also immunohistochemically detected, consistent with its thyroid origin. However, the tumor was negative for calcitonin both by immunohistochemistry and in situ hybridization, hence, not meeting the definition of MTC. Despite the loss of calcitonin expression, immunoreactivity for the calcitonin-gene-related peptide was detected in the tumor. Somatic gene mutations of RET, H-RAS, K-RAS, or BRAF were not detected in this case. A limited number of calcitonin non-producing thyroid neuroendocrine tumors are available in the scientific literature available in English, and its etiology and clinical manifestations remain largely unknown. Our case, along with the rare, previously reported cases, suggests that calcitonin non-producing neuroendocrine tumors of the thyroid gland are most likely derived from C cells, but should be differentiated from ordinary MTCs.

The Co40Fe40B20(CFB)/MgO/CFB/MgO/CFB-based multilayer was prepared by conventional magnetron sputtering and utilised in the fabrication of double magnetic tunnel junctions (DMTJs) for which the middle CFB layers were island-shaped. By analysing the magnetic property of the CFB islands with Langevin’s equation, it was possible to identify their diameters of 7.6, 8.9 and 11.0 nm; accordingly submicron-scaled DMTJs were fabricated to investigate single-spin transport phenomena. The coulomb staircase and the oscillatory tunnel magnetoresistive (TMR) were able to be observed at 6 K, where the TMR ratio was enhanced up to 60%, which is the highest value ever achieved in this structure.

Magnetic tunneling junctions with Co 40 Fe 40 B 20 /Co 70.5 Fe 4.5 Si 15 B 10 composite free layer have been fabricated and annealed at different temperatures to obtain the highest tunneling magnetoresistance. The field and temperature dependences of the low frequency noise have been measured to understand the origin of noise. The random telegraph noise has been observed at low magnetic field, and the corresponding fluctuating moment is estimated to be 4.8×10 5 μ B with an effective area of 240 nm 2 . The dependence of noise on temperature was coincident with the thermally activated kinetics model above 30 K while it deviated from this model below 30 K. Studying the origin of the low frequency noise is helpful to reduce the noise level in MTJs.

Protective surface treatment via several kinds of cost-effective thermal spraying alternate materials was developed and investigated in this study for heat exchanger tubes in waste incinerators with quite aggressive environment. Different thermal spraying materials including Fusible Ni-SA-a, Fusible Ni-SA-b, Fusible Ni-SA-c, NiCr-TS and NiCr-WEL were investigated to evaluate their performance of corrosion resistance. Three corrosion tests including high-temperature wettability test, long-term adhesion force experiment and hot corrosion test were performed, respectively. As has been proven from experimental results, the specimen coated with Fusible Ni-SA-c exhibited high contact angles in both air and simulated flue gas condition, which indicated a low ash wettability and liquid-bridge force. The coatings of Fusible Ni-SA-c and Fusible Ni-SA-b resulted in quite low adhesion force between ash and specimen, illustrating their good performance to improve the tube corrosion resistance. Besides, the weight losses of specimens coated with Fusible Ni-SA-c and Fusible Ni-SA-b due to corrosion by ash were noticeably decreased, in particular Fusible Ni-SA-c caused almost zero corrosion. Fusible Ni-SA-c decreased the amount of ash deposition on the tube surface of SUS304 by 35%. These corrosion tests supported Fusible Ni-SA-c as thermal spraying material with excellent corrosion resistance, which is able to prevent the heat transfer surface from high-temperature corrosion and thus enhance the service-life of the tube. Furthermore, among these corrosion tests, it was found that the high-temperature wettability test is an effective approach to evaluate the performance of different corrosion-resistant materials.

A BiFeO3 (BFO) film is epitaxially grown on an (La0.3Sr0.7)(Al0.65Ta0.35)O3 (LSAT) substrate to investigate the lattice mismatch effect on the domain structure and lattice strain status within the BFO film. Atomic resolution scanning transmission electron microscope image, selected area electron diffraction (SAED) patterns, and X-ray reciprocal space mapping (XRSM) data clearly reveal that the lattice strain originating from the lattice mismatch between BFO and LSAT is relaxed by causing misfit dislocations in the BFO film. The SAED and XRSM data indicate that the crystal structure of BFO film is rhombohedral with the space group R3c. In particular, XRSM data acquired along two different in-plane orientations reveal that the BFO layer consists of two different domains that were 90° off each other with respect to the surface normal orientation. An atomistic model based on the crystal orientation relation found by SAED and XRSM shows that (1) the ferroelectric polarization axes of both domains are 35.6° with respect to the BFO film surface and (2) the two domains are consistent with the so-called 71° (and/or 109°) ferroelectric domains reported previously. The lattice mismatch of ∼2.8% calculated based on the epitaxial relation is proposed to be too large to be stored as elastic strain energy within the BFO layer.

We report on the large-scale integration of graphene layers over a FePd perpendicular magnetic anisotropy (PMA) platform, targeting further downscaling of spin circuits. An L10 FePd ordered alloy showing both high magneto-crystalline anisotropy and a low magnetic damping constant, is deposited by magnetron sputtering. The graphene layer is then grown on top of it by large-scale chemical vapor deposition. A step-by-step study, including structural and magnetic analyses by x-ray diffraction and Kerr microscopy, shows that the measured FePd properties are preserved after the graphene deposition process. This scheme provides a graphene protected perpendicular spin electrode showing resistance to oxidation, atomic flatness, stable crystallinity, and perpendicular magnetic properties. This, in turn, opens the way to the generalization of hybrid 2D-materials on optimized PMA platforms, sustaining the development of spintronics circuits based on perpendicular spin-sources as required, for instance, for perpendicular-magnetic random-access memory schemes.