Superconductivity found in meteorites

Abstract

Meteorites can contain a wide range of material phases due to the extreme environments found in space and are ideal candidates to search for natural superconductivity. However, meteorites are chemically inhomogeneous, and superconducting phases in them could potentially be minute, rendering detection of these phases difficult. To alleviate this difficulty, we have studied meteorite samples with the ultrasensitive magnetic field modulated microwave spectroscopy (MFMMS) technique [J. G. Ramírez, A. C. Basaran, J. de la Venta, J. Pereiro, I. K. Schuller,Rep. Prog. Phys.77, 093902 (2014)]. Here, we report the identification of superconducting phases in two meteorites, Mundrabilla, a group IAB iron meteorite [R. Wilson, A. Cooney,Nature213, 274–275 (1967)] and GRA 95205, a ureilite [J. N. Grossman,Meteorit. Planet. Sci.33, A221–A239 (1998)]. MFMMS measurements detected superconducting transitions in samples from each, above 5 K. By subdividing and remeasuring individual samples, grains containing the largest superconducting fraction were isolated. The superconducting grains were then characterized with a series of complementary techniques, including vibrating-sample magnetometry (VSM), energy-dispersive X-ray spectroscopy (EDX), and numerical methods. These measurements and analysis identified the likely phases as alloys of lead, indium, and tin.

Calculation of a magnetic force acting on small superconducting celestial bodies

“…Naturally occurring superconducting phases were recently found by Wampler et al [1] in the samples from two meteorites-iron meteorite Mundrabilla and ureilite GRA 95205 using magnetic field modulated microwave spectroscopy [2]. Some other hints were observed earlier by Guenon et al [3].…”

“…The assumed uniform, spherical form of a superconductor is rather unlikely. It can be expected that a superconducting body, similarly to the one described at Wampler et al [1], would contain multiple smaller, disjointed domains with complex shapes. The elongation of the superconductor interface in the direction of a magnetic field gradient can lead to a larger effective F m .…”

“…Notably, T c of tin is 3.72 K and of lead is 7.19 K [7]. It was the alloy of these elements (along with indium), which was detected by Wampler et al [1]. Another candidate for a space superconductor are some types of diamonds.…”

Nodal superconductivity in miassite Rh17S15

“…Elemental metals are prone to producing oxides, sulfates, nitrates, etc, while elemental lead and tin exist in single crystalline form in some ores as rare exceptions. Their mixture with indium is responsible for traces of superconductivity found in meteorites [1]. The two minerals known to show superconductivity are covellite, CuS, with superconducting transition temperature T c =1.6 K [2,3] and parkerite, Ni 3 Bi 2 S 2 , with T c ≈0.7 K [4,5].…”

Cosmic superconductivity

“…Lead, with a superconducting transition temperature of 7.2 K, sometimes occurs in its native state, but superconductivity in natural samples has never been reported. In fact, until now the only previous claim of superconductivity in a natural material has been in the rare layered copper sulfide mineral covellite 1 , which has a transition temperature of about 1.6 K. Now Wampler et al describe evidence of superconductivity in phases within two meteorites 2 . They used a technique called magnetic field modulated microwave spectroscopy (MFMMS), an ultrasensitive method that identifies a superconducting transition as a peak in the derivative of microwave absorption with applied magnetic field, as the temperature is changed 3 .…”