sductor▲▲Hoi AHFig 1 Schematic diagram of interface between normal and superconducting phases: a) TypeI superconductor; b)Type Il superconductor ns-density of superconducting electronsMagnetic properties of these two superconductor types are essentially different( Fig 2) Thisductors), where the Ginzburg-Landau parameter ae <1/2(Ginzburg &La950; Ginzburg, 1955), the n-s interphase surfac>0 For thisder theact of magnetic field an intermediate state, as shown by LDLandau (Landau, 193ated in those superconductors of arbitrary shape (with thedemagnetizing factor n *o)where the layers of the normal and superconducting phasesrMAbFig 2
(a)The induction in thelinder as a function of the applied field for Type I andType II superconductors; (b) The reversible magnetization curve of a long cylinder of Type Ind Type ll superconductor(Afteronducting alloys), where a >1//2, the n-s interphaseetrates thesethe abrikosov vortexAbrikosov, 1957) As indicated by AA Abrikosov(Abrikosov957 the idea aboys turning into Type ll superconductors at the value of the1/√2brought forward by LD Landau
he Discovery of Type ll Superconductors(Shubnikov Phase)On April 3, 1935 K Mendelssohn and JR Moore(Mendelssohn Mo) in which they supported the existence of theto the multiphase alloy Pb+70wt% Bi The article put forwardonnection thinomalously high critical fields serving as current paths( for more detail, refer to theMay 30, 1935, in Discusperconductivity and Other LowAlux dependedthe purity, lead with 1%1vestigated, and the results actually shouted that the "frozen in"increased withthe addition of the second component
) Nonetheless, the existence of the Mendelssohn Spongeount for the magnetic field penetration at H H in Type ll superconductorsical sample of single crystal Pb+66,7at %TIfield(Rjabinin Shubnikov, 1935b0,71MMH25Fig 14 Temperature dependents of H1, Hz, Hei for single crystal Pb+66, 7at TI(Rja
sductorNote that in the same 1935 C J Gorter(Gorter, 1935)and H London(London, 1935), whilearrived at a conclusion that in magnetic field they had to be delaminated into thin(smallerletic fieldS Casinir-Jonker, 1935b: De Hiir- Jonker, 1935c), using theshowed that actualltore the first trace of resistance, and that the penetrationsoln 8 Moore, 1935), and Riabinin and shubnikov (Rjabinin 8 shubnikov, 1935aRiabinin 8 shubnikov, 1935b), measuring the B-H curve of a long rod of superconducting alloThe Mendelssohn Sponge hypothesis was predominant for about 25usedlainuld be just enough to mentionhdty" by VL Ginzburg edited by L D Landau(Ginzburg 1946) where it isThe superconductor properties are strongly dependenfiessubstantially differenf to those of the pureperconductors" The Mendelssohn Sponge hypothesisater foundrefer foinstance, to( Goodman, 1964; Berlincourt, 1964: Morin et al, 1962; Berlincourt, 1987))We shall reiterate that nearly all of the alloy samples studied in all above works(exceptEven though 9 out of 13 of the above-mentioned experimental studies on superconductingalloys pursued for 7 years by men of science from different countriWilhelm, K Mendelsson, L V, Shubnikov with co-workers(De HaasVoogd, 1930; De Haas voc931b; De Haas Casimir-Jonker 1935a: De Haas &Casimir- Jonker, 1935b; De Haas Casimir- Jonker 1935c: Casimir-Jonker De Haas, 1935ter time Suffice it to say that the fundamental pubi ) they i
e published in high-ratinRyabinin Shubnikov, 1935a; Ryabinin Shubnikov, 1935b)wermun phys, Lab Univ leidenLion handbuch der956edition(Serin, 1956: Bardeen, 1956)did not mention any of the above-said research at al3 Discoveryproperticting alloythe globe by the time when the pashubnikov, V, I Khotkevich, G D Shepelnikov et al, 1937) saw the light Those paperssubmitted for publication on April 11 and November 2, 1936, respectivcontained theroad temperatuingle -crystal metals and single crystals of single- phase alloys Pb-Tl(0 8;2550wt %)and Pb-In(2: 8wt %) whichvery carefully annealed at the pre-meltployed for research into Type lI superconductegion of the impurity concentrations there is a region of the solid solution(Fig 7, 15)which
he Discovery of Type ll Superconductors(Shubnikov Phasewas stable down to the cryogenperatures, thus opening up new vistas for makingthe concentration effectsAtomic percent IndianFig 15 Binary phase diagrams of the alloy Pb-lIn(After Massalski, 1987)High-quality single-crystals of the alloys that had the length-to-diameter ratio 2 10 wereing to the Obreimov-Shubnikov technique(Obreimow Schubnikeagnetic field was measured oyponse of the ballistic galvanometer, while thas fast removed (or brought inkgalvanometer The entire sample magnetization cycle went by the consecutiIn their articles(Schubnikot1936: Shubnikov et al, 1937) the authors implying thblished(Rjabinin Schubnikow, 1935a; Rjabinin Schubnikow, 1935bsaid again thapuperted out thefic properties of superconducting alloy by the disintegrationdes, the authors indicated that: "De Haas and Casimir- Jonker(De Haas Casimir-Jonker935b) found for the first fime that, for PbTl2 and BisTls, there exists thhe critical magnetic field whichpenetrates into fhe alloy but does not break up the superconductivity: fhaf is why it is considerably
Shubnikov et al (Schubnikow et al, 1936; Shubnikov et al, 1937) discovered thatThere was a boundary over the impurity concentration in the superconducting alloysbefore which their magnetic properties resembled the magnetic properties of puresuperconductors - the total Meissner Effect at fields that were smaller than critical andudden disruption of the superconductivity upon further magnetic field increasing( Fig 16day viewpoint: with the growth of the Ginzburg-Landau parameter ae) the magneticperties of the alloys got to differ drastically from those of thMeissner Effect existed only as far as the magnetic field Hel, and upon further fieldcreasing the alloys remained superconducting as far as He, with the magnetic field
sductorgradually penetrating into the alloy Fig 17, 18 gives the results ofch on alloys pb-Tldoes that for pb-no,9 T422KroFig, 16, The inductital Sn, Hg, Pb and single-crystal alloy Pb+0, 8wt %TI in longitudinal magnetic field(After SchubnikoWithg the impurity concentration (ie
with a growing parameter ae)the intervaln He and he2 broadenedsmaller, while He2 grew Fig, 20 presents datafor alloys Pb-Tl4 The unusual propertieson the superconducting alloys could not be attributed to5 The difference in free energy of magnetized and normal superconductors was given by
he Discovery of Type ll Superconductors(Shubnikov Phase)where M-the magnetization, while the entropy difference was produced by the derivativeFig 17 The induction curve of long cylinders of single-crystals of alloys Pb+2, 5wt%TI5wt%Tl(After Schubnikow et al 1936)Shubnikov et al, 1937) for these alloys indicated that in this case, as in the case of puresuperconductors, the researchers dealt with magnitudes of the same order thatlikewise dependent on temperature
For this reason, the jump in the heat capacity duringthe superconducting transition in zero magnetic field for the alloy was comparable to that ofperconductordonducting alloys indicated that they had no solidsolution disintegration going in them( the alloys were single-phase)which conflicted withhe old ideas about their superconducting properties being related to the inhomogeneitiesIn this way, it was exactly in the research papers by shubnikov, KHRyabinin(Schubnikow et al, 1936 Shubnikov etT that a well-substantiated andcorectde as to the existence ofsuperconductor type Thisconclusion clashed with all the preceding research that had explained the previouslybtained results by compositional and structural inhomogeneities of sampleEven though the published results by LvShubnikov et al (Schubnikow et al, 1936:7) became instantly known abroad (wilsoShoenberg, 1938; Jackson, 1940; Burton et al, 1940; Mendelssohn, 1946: Shoenberg, 1952)ahead of their time and their significance had not been apprefoThe reason for this was clearly stated in the Nobel Prize lecture by V L Ginzburg (Ginzburg,superconductivity (Ginzburg Landau, 1950), remarked that regarding oryms lacking, and landau and l likemany others, believed that alloys are an unsavory business, and did nof take an interest in thenmtricting ourselves to the materials with a ao for wich ons>0, ie type I superconductors
sductorluch laterinzburg-Landau theory had been constructed (Ginzburg landauby shubnikov and his7)that" The most spectaculaapplicationof such superconductorsChandrasekhar, 1969) Berlincourt(Berlincourt, 1987) noted very justifiably that Shubnikoet al did not use in their research the CJ Gorter(Gorter, 1935)and H Londons Theory(London, 1935H London referred toShubnikov's et al results to support their theories
It would be very apt to cite theR Kipling"Oh, East is East, and West is West, and never the twain shall meetop Ta422K[8 pinkFig 18 The induction curve of long cylinders of single-crystals of alloys: Pb+15wt%T1Pb+30wt%ll: Pb+50wtAfter Schubnikow et al, 1936The discovery discussed above waspanied by a dramatic conflict of creativity andgreat human tragedy affecting the lives of two prominent scientists, LD Landau and
he Discovery of Type ll Superconductors(Shubnikov Phase)e Big PhysicsProblems of High-Temperature Superconductivity (2004)
L Ginsburg created the phenomenological theory of superconductivity(Ginzburg &e Landau, 1950: Ginzburg, 1955)wherein the Ginzburg-Landau parameter aebrought into the picture In his paper published in 1997 and titleperfluidity (what I could and could not donzburg, discussing the theor(Ginzburg Landau, 1950: Ginzburg, 1955) pointed out quite cleaactually overlooked the possibility of eristence of Type lI superconductors"(Ginzburg, 1997)n august 6, 1937 L V Shubnikov was arby the joint verdict of October 28, 1937, handed down by the odiousasrehabilitated in 20 years)(Fig 21)DLandauested on April 27, 1938,as a staff scientist at Institute of physicalProblems, however in a year he was pulled out of jail by P LKapitsa's interventionLD Landau was also granted the pardon posthumously only in 1990) As a reminder, we
he Discovery of Type ll Superconductors(Shubnikov Phase)ce the pioneering experimental research on superconductingloys under applied magnetic field to understand fully the Type ll superconductivityThe theory of Type II superconductors has been expounded in detail over the past 45 yearsof reviews andfragmentarily either at the early stages of the research(Bu34: WilsonRuhemann, 1937: Shoenberg, 1938: Jackson, 1940; Burton1940; Ginzburg, 1946;rg, 1952)or later on(refer to the aut(Mendelssohn, 1964al 1969: Ande09; Chandrasekhar, 1969: Serin, 1969: Hulm MatthiasHet al, 1981; Pippart, 1987; Berlincourt, 1987; DahL, 1992; Dew-Hughes, 2001)and also toSharma &z Sen, 2006: Slezov Shepelev, 2008: Karnaukhov Shepelev, 2008, Slezov &x2009) Therefore, thehidden from view to many of the International Scientific Communitye shall remind that H Kamerlingh Onnes(Physical Laboratory, University of Leiden),as the first with his co-workers to takeerconducto(Kamerlingh Onnes, 1914; Tuyn Kamerlingh Onnes, 1926; Sizoo et26: De haas et1926, De Haas voogd, 1931a) In particular, it was found that superconductivity in purevalue H(in the case of the demagnetizing factor n=0), which manifested itself in a sudderrestoration of electrical resistance of the samples from zero to such value that correspondes、-12·28T=292KFig 3 Sudden change of electrical resistance of wire sample of single crystal tin at T
I hotkevich, G D,Shepelev, Yu N Ryabininet al, 1936, Shubnikov et al, 1937)
sductorm the feature of electric properties of Type I superconductorsPtivity whichn 10-2 Q2-cm), the second fundamental characteristic of pu1933 W Meissner andR Ochhsenfeld (Physikalische Technische Reichsanstalt) foundleissner Ochsenfeld, 1933)that a magnetic field which was smaller than He dieer the impact of an applied magneticvalue H the pure superconductor magnetization M and induction B also changed withmp(Fig 4) These values are relatM=(B-H)/4nf flux feffectAny discovery is generally preceded by a preparatory period Thllowing the actual discovery the recognition is accorded Some time after that one can look1 H/HcH/HeFig
4 a) Magnetizationpure superconducting long cylinInterestingly enough, even before the Meissner effect was discovered,Haas, J Voog1929) a distinction between the behavior in applied magnetic field of electrical resistance ofcrystalperconducting alloys and that of pure superconductors It appeared that inrod specimens of the alloys Bi+ 375at%TI, Sn + 58wt% Bi, Sn +281wt%Cd(the latter twoeutectic Pb+ Bi and in the alloys Pb-Bi (7wt%; 10wt%; 20wt%), Sn+ 402wt %Sb(De HaasVoogd, 1930), in the alloys Pb 15wt%Hg, Pb 40wt,Tl, Pb + 35wt %Bi, the eutectic ADe Haas Voogd, 1931b) the disruption of superconductivity occurred acrebroasinterval of magnetic fields irrespective of the orientation of the field running parallel, ie at
he Discovery of Type ll Superconductors(Shubnikov Phase)n O(Fig 5), or perpendicular(Fig 6)to the axis of cylindrical specimens, i e at n-12 2) Aserg, 1952), for superconmuch less difference between fite cuthere is for60x10aBell1=Sn-Bio TalseFig
5 The resistance ofing long cylinder for polycrystalline Sn-Bi alloy(AfterDe Haas Voogd, 1929)and Pb-Tl alloy in longitudinal magnetic field(After De HaasVoogd, 1930400/ Pb-B△335°Bis TLyBfieldDuring studies on the electric properties of the eutectic Pb-Bi, while decreasing appliedmagnetic field from He to zero, (De Haas Voogd, 1930) found a clear-cut hysteresis about@ -(De Haas et al, 12 composition of research alloy samples are given: for alloys Sn-Bi,Sn-Cd,Pb30), Sn-Sb in(Van Aubel et aL, 1929), Au-Bi in929b)
sductorauthors wrote later so very many scientific papers Much later, it was showngnetic field that ran parallel to thsurface in the interval H2
8)the majority of the alloys studied by WJ De Haas, J Voogd (De HaasFig 7 Binary phase diagrams of the alloys TI-Bi, Pb-Tl, Pb-Bi, Sn-Sb(After Massalski, 1987)
e Discovery of Type ll Superconductors(Shubnikov PhaseFig 8 Binary phase diagrams of the alloy Hg-Pb(After Massalski, 1981929: De Haas Voogd, 1930; De Haas voogd, 1931b)(except the alloys Pb+Tl, Pb+Bwt%; 10wt %) and Pb+15wt%Hg)hadthanhaseeneous as were the alleth the eutectics snI-Cd, Pb-Bi, Au-Biovery in the eutectic Pb-Bi of preservation of superconductivity under applied fieldsder of 2T allowed w ) De Haas, J Voogd(De Haas voogd, 1930)to bring back to lifein Leid g solenoids withoutting much energy
Halue of( Rjabinin &Schubnikow, 1955aMendelssohn, 1966)reasoned that the resolution of this challenge, as it were, called ooAThe subsequent experimental research indicated that not only the behavior of the electricalproperties, but also that of the magnetic ones, in superconducting alloys were different to thproperties of the pure superconductors In the span of36 therethrilling hurdlethe studies on magnetic properties of superconductingbetween scientists ofcountries out of the five that had liquid helium at their laboratories at that momentConsidering that the superconductors possessed a large magnetic moment, the methods usedin the works belowbased on the standard magnetic measurements Using a fluxmeter orcharacteristicthe coil that surrounded thdtof the coil at constant temperatures andtic fields, or upon turning oroff the constantring stepping upor down the magnetic field little-by-littlethe entire range from zero to He and backCanadian scientists FGAIonto) submitted a paper for publ(Tarr &e Wilhelm, 1935)on Sepwhich contained the results of their studies on magnetic protductingercury, tin, tantalum, as well as the alloys with the eutectic Pb+Sn(40wt %; 63wt%; 80wt%nd the multiphase alloy Bi+27 1wt% Pb+229wt%Sn, observable under the impacpplied magnetic field Fig9 presents the phase diagram of the ternary alloy In particu
he Discovery of Type ll Superconductors(Shubnikov Phase)In this way, it turned out that there were three characteristic fields in the superconductingonset of a gradual restoration of electrical resistance and a field of the complete transition ofhe alloy into the normal(Fig 11) ArticlesJ De Haas and JM
Casimir-Jonker on December 7, 1934 to the prestigious"Nature"(whichan it on January 5, 1935 (De Haas Casimir-Jonker, 1935b))and to theaturthe University of Leiden( De Haas Casimir-Jonker, 1935c)(refer also to the paper(casin:%onker De Haas, 1935)submitted for publication on July 29, 1935)6T421°K▲T370T=201Fig, 10 Penetration of magnetic field into the superconducting alloys Bi+37, 5at %TI (left)state(T>Tc)(After De Haas Casimir-Jonker, 1935cFig 11 Tedependence of the incipient penetration of magnetic field into thenducting alloy pb+64, 8wt %rl The hatchedpenetration in magnetic field according to the electrical resistance measurement data(AfterDe haas Casimir- Jonker, 1935
sductor12CLaboratorys Researchers, 1933 From left to right: (the first line)Rudenkod), NM Zinn( third), ONTrapeznikova(fourth), Yu N Ryabinin(fifth)th);(the second line)G DShepelev(third)LV Shubnikov( fourth), IPKorolyov(fifth), V
l Khotkevich(sixth),VA Maslov (ninth)LV Shubnikov, who was known to be working very successfully with wJ De Haas fromautumn of 1926 until summer of 1930 at Kamerlingh Onnes Laboratory (it was there exactlythat the Shubnikov-De Haas Effect the periodic magnettance oscillations in purescovered), knew well about his research intog alloys Having created(UPh1935(Rjabinin Schubnikow, 1935a)(itssummary published by the"Nature"on April 13, 1935(Rjabinin Schubnikow, 1935bYu N Ryabinin and LVShubnikov supported the existence of the incipient penetrationcrystal Pb-35wt%les of those alled been studied earlier bwJ De Haas, J Voogd (De Haas &x Voogd, 1930; De Haas Voogd, 1931b)and designated itorrespondingly as Hel It was confirmed that prior to the field He there was the magnetihichgradually increased withapplied field the authors also measured the