Recently scientists observed and measured tantalum atoms dispersed on graphite when exposed to hydrogen microwave plasma caused the Ta to catalyze the formation of sp3 C for nucleating and growing diamond.   See { Diamond synthesis by hydrogen reducing tantalum oxide in graphite at atmospheric pressure | Journal of Applied Physics | AIP Publishing } Recently also a different team of scientists observed that putting a tungsten wire in the microwave plasma during methane hydrogen microwave deposition of diamond led to faster diamond growth of better crystallinity.  { Enhancement of crystalline quality of homoepitaxial (100) diamond by microwave plasma chemical vapor deposition with a tungsten wire - ScienceDirect }  Here Reginald B. Little gives explanations of both these phenomena of tantalum (Ta) and tungsten (W) for catalyzing diamond on basis of his prior 2006-07 Treatise on the Resolution of the Diamond Problems { Treatise on the Resolution of the diamond problem after 200 years - ScienceDirect } by positive NMMs of Ta and Tungsten.  On such basis, RBL explains why lead (Pb) does not also catalyze the diamond as Ta and W do.  RBL further argues this is all evidence of scientific validity of his more recent prediction of using heavier stable carbon isotope (13C) to accelerate nucleation of BC8 diamond rather than use of  less massive stable carbon isotope (12C), as 13C has positive NMM and 12C has zero NMM.

First considering the observation of Tantalum atoms to nucleate diamond from graphite as reported in April 2025 { Diamond synthesis by hydrogen reducing tantalum oxide in graphite at atmospheric pressure | Journal of Applied Physics | AIP Publishing }. The 6s2 4f14 5d2 electronic configuration of Tantalum has 4 valence electrons.  RBL notes in the plasma under microwaves that the microwaves excite electrons in the tantalum so the electrons have 6s2 4f14 5d0 6p2 so the tantalum more easily rehybridize 6s2 and 6p2 by Little Effect and transfers the angular momentum to the carbon atoms with 2s2 2p2 for tantalum to more easily rehybridize 6sp3 electronic orbitals and the transfer to carbon atoms will rotate the 2s2 2p2 to 2sp4 for forming diamond.  In 2000-03, RBL proposed and discovered that under strong magnetization the orbitals of the atoms can be organized to caused better nucleation of greater crystallinity over larger space during shorter time.  Recently Scientist in Austria, Australia and China obtained evidence in 2025 supporting, such 2000-03 discovery of RBL of strong magnetic field orienting and polarizing orbitals by experiments on excited Helium atoms in strong magnetic field orienting orbitals.  See {Electron Orbital Angular Momentum Polarization in Neutral Atoms  }

But with such magnetic field in the plasma orienting the orbitals, I go back and consider why the tantalum 'fix' the electrons in sp3 hybridization and why the sp3 hybridization exist in the atoms before bonding. Some may wonder why the 6sp3 state in the Ta is stable as there is no bonding.  RBL proposed in 2003 that the magnetization stabilize the sp3 hybridization of the atoms.  The magnetic moment of the unpaired electrons stabilize the sp3 preventing the electrons to relax to 6s2 6p2.  The nuclear angular momentum acting on the electronic spins.  The lone electronic spins in the s and electronic spins in p increase the interaction and mixing for hybridizing relative to non-lone interactions of e e bosons in the s and p orbitals.  The nucleus by positive nuclear magnetic moments (NMMs) further stabilizes the hybridization.  The hybridization causes stronger interactions of the electronic orbital momentum with the nuclear orbital momentum to stabilize the hybridization.  The positive NMM distorts the s and p orbitals to induce stabilizing hybridizations.  RBL noted this in 2005 for Cu and Ag as the nuclear coupled spin orbital shifts the electrons in s and d orbitals of Cu and Ag.  See { International Journal of Physical Sciences - magnetocatalytic adiabatic spin torque orbital transformations for novel chemical and catalytic reaction dynamics: the little effect }

The microwave plasma may more easily rotate the electronic orbitals of Ta than rotate the electronic orbitals of carbon.  The densities of states of 6s 5d 6p is greater and requires less excitation energy of the Ta atoms relative to C atoms having lower density of states of 2s and 2p.  The tantalum (Ta) also has nuclei of positive NMMs.  Such positive NMMs pull the 6s2 6p2 electrons distorting toward the Ta nucleus for strong field and weak field to twist the 6s2 6p2 to 6sp3 hybridization relative to the carbon atoms having mostly 12C.  The 12C has zero NMM and the nucleus of 12C less helps twist the 2s2 2p2 electrons to 2sp3 hybridization due to the zero NMM of the 12C nucleus, relative to the Ta having all positive 2.7 NMM for assisting the rotating of the 6s2 6p2 orbitals to hybrid 6sp4 orbitals.  The Ta thereby fix the carbon transferring the 6sp3 electrons to carbon.  RBL already captured this effect for oxygen helping to fix carbon due to the electron excess O and the stronger electron --- electron interaction in 16O relative to 12C for 16O to more easily rehybridize to 2sp3 hybrid orbitals and transfer the electrons to carbon.  But the effect is weaker as the oxygen is more electronegative and less push electrons into carbon.  But RBL also proposed that Si can help carbon rehybridize to sp4 for forming diamond and Si is less electronegative relative to Carbon so silicon pushes the sp3 electrons into carbon.  But more so as Ta is 3 rows lower in periodic table than Si so thereby Ta can transfer the sp3 hybridized orbitals more readily into C to explain the diamond nucleation in the microwave plasma by exposing the carbon to Tantalum atoms.

But RBL explains further.  RBL can explain why researchers observed formation of diamond when tungsten is placed in the plasma of CH4 plasma. { Enhancement of crystalline quality of homoepitaxial (100) diamond by microwave plasma chemical vapor deposition with a tungsten wire - ScienceDirect }  The tungsten form tungsten atoms and the tungsten atoms rehybridize the 6s2 4f14 5d3 electrons to 4f14 6sp5 and transfer these electrons to the carbon atoms for carbanions and the carbanions sp3 bond to accelerate diamond!  In comparing tungsten to tantalum, the effect of tungsten is less as tungsten (W) has smaller 0.117 NMM than tantalum (Ta) with 2.7 NMM and the relative abundance of 183W (tungsten) is only 14.3% relative to larger 2.7 NMM of Ta and its 99% relative abundance.  But why does lead (Pb) not catalyze diamond in this way as lead has 6s2 4f14 5d10 6p2 electronic configuration.  The Pb has unstable nuclei that may not stabilize the 6sp3 hybridized state. Pb has less positive NMM with only 207Pb having +0.58 NMM at 22% relative abundance.  The other nuclei (204Pb with 1.4% relative abundance, 206Pb with 24% relative abundance, and 208Pb with 52.4% relative abundance) have 0 NMMs.  The 207Pb has lower relative abundance of 22% and much smaller + NMM for twisting the hybridization relative to the 99% relative abundance Ta and its 2.7 NMM for better twisting the hybridization of the 6s2 6p2 electrons by Ta!    It is important to note the large positive NMM of Ta relative to Pb.  The smaller + NMM of 207Pb relative to the larger positive NMM of Ta is the reason Pb is not able to as easily catalyze diamond formation from carbon atoms in the plasma.

These effects of positive NMMs of Ta and W for nucleating diamond in the microwave plasma give support for 13C to be better reagent than 12C for nucleating and growing BC8 superdiamond as 13C has positive NMM and 12C has zero NMM.  Just as the positive NMMs of the Ta and 183W can twist the electrons to sp3 hybridization for transfering sp3 hybridized electrons to carbon for sp3 C-C bonding to diamond, the 13C internally by its positive NMM can twist its electrons under laser and pressure to more easily rehybridize 13C relative to 12C due to 12C lacking internal positive NMM!  See recent prediction of such by Reginald B. Little { Decomposition of PFAS and Synthesis of BC8 Super-Diamond: Rotations of Electromagnetic Waves for Novel Chemical Dynamics | European Journal of Applied Physics }.