Foundation earthing of container substation treated as a building

Artykuł podnosi aspekt stosowanych materia-łów na uziemienia sztuczne i przewody łączące uziom sztuczny łączony z uziomem fundamentowym stacji elektroenergetycznej.The article is focused on materials used for external earthing and conductors connecting the external earthing system with foundation earthing of the substation

57Fe Mössbauer effect study of Nd-Fe-B hybrid bonded magnets

An investigation of magnetic interaction between the particles of hybrid bonded magnets based on mixtures of Nd-(Fe,Co)-B and strontium ferrite powders was carried out. An enhancement of the magnet remanence and coercivity caused by the interaction between their components was observed. From Mössbauer effect study, it results that this enhancement can be correlated with the increase of an average hyperfine field at Fe sites in Nd-(Fe,Co)-B magnets with the strontium ferrite addition

Effect of Preparing Conditions on the Phase Constitution and Magnetic Properties of Nd-Pr-Fe-Zr-B Alloy Ribbons

The aim of presented work was to study influence of preparing conditions on phase constitution and magnetic properties of the RE-Fe-B nanocomposite magnets doped with Zr. X-ray studies carried out for samples obtained under lower pressure of Ar atmosphere (0.6×10⁵ Pa) revealed higher ability to formation of nanocrystalline structure. In case of higher pressure of Ar (0.8×10⁵ Pa) it was possible to obtain full amorphous ribbon during melt-spinning process. The best magnetic properties (means the higher values of coercivity field $\text{}_{J}H_{c}$, remanence $J_{r}$ and maximum energy product $(BH)_{max})$ were measured for sample prepared with the lowest copper wheel speed 20 m/s and higher pressure of Ar (0.8×10⁵ Pa)

Structural and magnetic properties of the as - cast Nd10Fe83Zr1B6 ribbons, studied by X-ray diffraction and Mössbauer spectroscopy

The Nd10Fe83Zr1B6 alloy ribbons, prepared by melt-spinning technique, have been investigated by X-ray diffraction (XRD) and Mossbauer spectroscopy. Magnetic properties were studied by Faraday balance and vibrating sample magnetometry (VSM). The ribbon samples were produced at various surface velocities of the copper wheel from 10 m/s to 20 m/s. The XRD and Mossbauer spectra analysis have shown that the ribbons consist of the soft magnetic alfa-Fe, hard magnetic Nd2Fe14B and disordered phases. The results showed that a uniform Nd2Fe14B/alfa-Fe nanocomposite structure with fine alfa-Fe grains can be obtained at an optimum velocity of the cooper roll of 20 m/s. The samples produced in these conditions had the best magnetic properties (mi0HC= 0.84 T, mi0MR = 1.05 T, mi0MS = 1.36 T, (BH)max = 160 kJ/m3) with strong exchange coupling between the hard magnetic Nd2Fe14B and soft magnetic mi-Fe phases. The amorphous phase existing between grains causes an increase in the remanence and remanence ratio

Wpływ obróbki termicznej na własności magnetyczne nanokrystalicznych taśm Nd9Fe84Zr1B6 wytwarzanych metodą szybkiego chłodzenia

The effect of the annealing on the phase composition and magnetic properties of nanocomposite melt-spun Nd9Fe84Zr1B6 ribbons has been investigated. From the X-ray diffraction studies confirmed be thermomagnetic curves measurements results that the microstructure of the material investigated is composed of a mixture of magnetically hard Nd2Fe14B and soft α-Fe, Fe3B nanosized grains. The small amount of undesirable Nd2Fe23B3 metastable phase has been found which do not decompose at the highest annealing temperature. The hysteresis loop measurements certify that the ribbon annealed at 863K show the best coupling between the hard and soft magnetic phases and thus the highest coercivity of 0.38T. The grain sizes increase with increasing annealing temperature causing the coercivity to be decrease.Zbadano wpływ wygrzewania na skład fazowy i właściwości magnetyczne taśm nanokompozytowych Nd9Fe84Zr1B6 otrzymanych metodą szybkiego chłodzenia cieczy na wirującym miedzianym bębnie. Badania mikrostruktury potwierdzają zależności krzywych termomagnetycznych, z których wynika, że stop składa się z ziaren o rozmiarach nanometrycznych faz: magnetycznie miękkich α-Fe, Fe3B oraz magnetycznie twardej Nd2Fe14B. Stwierdzono niewielką ilość niepożądanej metastabilnej fazy, która nie ulega rozkładowi przy najwyższej temperaturze wygrzewania. Pomiary pętli histerezy magnetycznej dla taśmy wygrzanej w temperaturze 863K świadczą o najsilniejszych oddziaływaniach pomiędzy fazami, twardą i miękką. Rozmiar ziaren wzrasta we wzrostem temperatury wygrzewania, powodując spadek koercji. Koercja taśmy wygrzanej w temperaturze 863K ma największą wartość, wynoszącą 0.38T oraz najmniejszy rozmiar ziarna fazy Nd2Fe14B

Struktura domenowa anizotropowego odkształconego na gorąco magnesu na bazie związku Nd-(Fe, Co)-B

The measurements of the recoil curves for the die-upset Nd-(Fe, Co)-B based magnets from different points on the magnetization and demagnetization curves have been carried out by means of the LakeShore vibrating sample magnetometer in an applied magnetic fields up to 2 T. From the recoil curves the so-called Wohlfarth's remanence relationship has been derived. From this it was deduced that the magnetic interaction existing between the magnet grains has a dipolar nature. The existence of the magnetic interaction has been confirmed by magnetic domain observations by using the magnetic force microscopy (MFM). In the area of interaction domains there is the fine scale magnetic contrast resulting from the dipolar interaction between neighboring grains.Za pomocą magnetometru wibracyjnego firmy LakeShore wyznaczono krzywe powrotne dla spęczanych magnesów Nd-(Fe, Co)-B w polu magnetycznym do 2 T. Na podstawie krzywych powrotnych wyznaczono zależność remeanencyjną Wohlfartha. Z zależności tej wynika, że oddziaływania magnetyczne pomiędzy ziarnami to dalekozasięgowe oddziaływania dipolowe. Obecność tych oddziaływań została potwierdzona przez obserwację struktury domenowej za pomocą mikroskopu sił magnetycznych (MFM). Oscylacyjne zmiany kontrastu, występujące w obszarach zbliżonych do wielkości ziaren, świadczą o istnieniu uporządkowania magnetycznego w tych obszarach, które jest wynikiem oddziaływania dipolowego między sąsiednimi ziarnami

Investigation of the Magnetization Reversal Process of High-Remanent Nd10Fe83Zr1B6Nd_{10}Fe_{83}Zr_1B_6 Alloy in the As-Cast State

In this work the magnetic properties of ribbons with composition of $Nd_{10}Fe_{83}Zr_1B_6$ obtained by using the melt-spinning method were studied. From the X-ray diffraction patterns the phase composition was determined. It was found that investigated alloy was composed of α-Fe and $Nd_2Fe_{14}B$ phases. From the peaks broadening the grain sizes of α-Fe and $Nd_2Fe_{14}B$ phases were estimated as equal to 20 nm and 40 nm, respectively. From the recoil curves the reversible $μ_0$ $M_{rev}$ and irreversible $μ_0 M_{irr}$ parts of magnetization and differential susceptibility $χ_{rev}$ and $χ_{irr}$ were determined as a function of an applied field. From these dependences it was found that the pinning of domain walls at the grain boundaries is the main magnetization reversal process. The interactions between grains were investigated by means of the δ M plot. It was stated that short range exchange interaction between grains of hard and soft phases are dominant and causes the remanence enhancement