Rare earth material quality is graded on REO (rare earth oxide) assay from 2N (99%) to 5N (99.999%), with the 99.999% Eu2O3 grade actively exported by Chinese suppliers and magnet alloys such as Pr/Nd and Dy/Fe sold as standard catalogue items [S1][S2].
The market spans oxide powders, rare-earth metals (Nd, Sm, Dy, Gd, Tb, etc.), master alloys (Al-La, Al-Ce, Al-Sc, Al-Er, Pr-Nd), salts (chlorides, nitrates, fluorides), and finished sintered NdFeB/SmCo magnets — each tier carries a different purity, particle size, and SQC requirement [S1][S3].
Oxide Purity Bands: 2N Through 5N REO, and What Each Grade Unlocks
Chinese processors routinely list Lanthanum Oxide (La2O3), Cerium Oxide (CeO2), Praseodymium Oxide (Pr6O11), Neodymium Oxide (Nd2O3), Samarium Oxide (Sm2O3), Europium Oxide (Eu2O3), Gadolinium Oxide (Gd2O3), Terbium Oxide (Tb4O7), Dysprosium Oxide (Dy2O3), Holmium Oxide (Ho2O3), Erbium Oxide (Er2O3), Thulium Oxide (Tm2O3), Ytterbium Oxide (Yb2O3), Lutetium Oxide (Lu2O3), Yttrium Oxide (Y2O3), and Scandium Oxide (Sc2O3) on published catalogues [S1][S3]. The high end of the range — Eu2O3 99.999% — is sold as a stable-quality grade in 50-piece MOQ lots, while thulium and cerium oxides are offered as 1–100 piece SKUs at US$ 0.5–2.8/piece depending on pack size [S2].
Selection is dictated by downstream use: 2N–3N (99%–99.9%) REO is adequate for glass polishing and catalyst carrier; 3N5–4N (99.95%–99.99%) is the working range for phosphors and NiMH battery precursors; 5N (99.999%) Eu2O3 and Tm2O3 feed red/blue phosphors and laser crystals where the alkali-earth and transition-metal residuals are tightly capped [S2].
Metals and Master Alloys: Vacuums, Lump Size, and Oxidation Risk
Distilled rare-earth metals (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, Sc) are sold as foils, rods, wires, ingots, and lumps; Nd, Pr, Ce, Sm, La are commonly described as "soft silvery metal that easily oxidizes in air," which dictates vacuum-pack or inert-gas packaging and limits skin-time during QC sampling [S1][S3].
Aluminium-based master alloys dominate the alloying feed for 6xxx-series auto and aerospace billets: Al/La, Al/Ce, Al/Er, Al/Y, Al/Sc, plus 10% rich grades (Al/La10%, Al/Ce10%, Al/Gd10%, Al/Sm10%, Al/Er10%, Al/Yb10%) [S1]. Pr/Nd alloy is the standard feed for sintered NdFeB magnet strip casting, while Dy/Ga and Y/Ni alloys are used as grain-boundary diffusion sources to lift coercivity in N52H/SH magnet grades [S1].
Magnet Spec Stack: NdFeB vs SmCo vs AlNiCo vs Ferrite
Sintered NdFeB remains the workhorse for traction motors and wind generators, with a complete chain from NdPr alloy → strip-cast flake → hydrogen decrepitation → jet milling → press/sinter → grain-boundary diffusion, and the typical rapid-prototype lead time quoted by custom-magnet integrators is 2–4 weeks for prototype tooling [S6][S9]. SmCo (Sm2Co17 / SmCo5) is specified where the upper-use temperature exceeds the NdFeB ceiling and where oxidation resistance matters; AlNiCo and ceramic (Sr/Fe ferrite) round out the catalogue for cost-driven instruments and high-T sensors [S1][S9].
A practical four-axis comparison for buyer-side selection: 1) energy product (BH)max — NdFeB up to ~52 MGOe grades, SmCo 18–32 MGOe, AlNiCo 5–9 MGOe, Ferrite 3–5 MGOe; 2) max continuous use temperature — NdFeB up to ~200 °C standard, ~230 °C with Dy/Ga diffusion, SmCo 250–350 °C, AlNiCo up to ~550 °C, Ferrite ~250 °C; 3) corrosion/oxidation resistance — SmCo > Ferrite > AlNiCo > NdFeB (surface-coated); 4) relative cost per kg of magnetic energy — Ferrite < AlNiCo < SmCo < NdFeB, with NdPr oxide and NdFeB scrap as the dominant cost stack inputs tracked weekly by price-reporting services [S1][S4][S9].
QC Test Methods, Certificates, and Documentation Buyers Should Demand
Lot acceptance testing for oxides, metals, and salts typically combines ICP-OES (inductively coupled plasma optical emission spectroscopy) for trace-impurity panels against Pr/Nd, Ce, La, and other lanthanide interference lines, XRF (X-ray fluorescence) for screening assay, ICP-MS where sub-ppm detection of U/Th is required, and loss-on-ignition (LOI) for hydrated salts and carbonates [S1][S3]. For metals, oxygen/nitrogen (LECO ONH) and carbon/sulfur (LECO CS) are reported alongside the metallic assay because interstitial O is the most common cause of brittleness in vacuum-distilled Nd and Dy [S1].
Process-side quality systems for Chinese processors generally sit on ISO 9001 with on-site XRF/ICP benches, and larger trading houses publish third-party SGS certificates on demand; Lianyungang Xinfu states its SGS audit linkage on its trade page and lists China Minmetals, Guangxi Non-Ferrous, and Jiangsu Guosheng as upstream counterparts [S3]. For US/EU-bound shipments, REACH SVHC declaration for lanthanides, RoHS compliance for finished magnets, and a separate conflict-mineral (3TG + REE) CMRT/EMRT template are now standard request items, while Saudi/Saudi-style SASO IEC 60079-x compliance is not part of the REE supply package [S3].
Price, Lead Time, and Sourcing Signals in Mid-2026
MagnetSearcher publishes daily NdFeB raw-material prices, sintered NdFeB blank prices, SmCo raw-material prices, and NdPr short- and mid-term price forecasts, and tracks industry events as a procurement reference [S4]. Prototype magnet programs from US/EU integrators run 2–4 weeks for rapid prototyping and design iteration, while full magnet-alloy orders from Chinese processing hubs (Bayan Obo feed, Ganzhou separation, Ningbo magnet strip) remain the price-setting layer [S4][S6].
US REE presence is still thin: TyTek Bakker, a Cincinnati-based assembler founded in 2001, sources qualified rare-earth products and builds magnetic assemblies, but operates as a small distributor rather than a primary oxide or metal refiner [S8]. On the magnet side, King-Nd runs a Ningbo production base established in 2008 with a complete industrial chain from permanent-magnet blank material to finished NdFeB products [S9]. For process plants that already spec NdFeB magnet materials and rare-earth alloys, the working spec sheet is identical in structure to other industrial material specs — fix grade, assay, test method, and standard before quoting.
To land a defensible PO, fix three things in the RFQ: (a) the REO assay band (3N vs 4N vs 5N) with the analytical method, (b) the impurity panel (Fe, Si, Ca, Al, plus U/Th if optics-grade), and (c) the magnet or alloy form factor with the relevant standard (e.g. IEC 60404 for magnetic materials, ISO 9001 for the QMS, REACH/RoHS for EU access). Track the next MagnetSearcher weekly NdPr forecast on 2026-08-06 and the next round of SGS-refreshed supplier data from Ganzhou/Jiangxi exporters as the live signals for sourcing decisions [S4].
For the relevant spec sheets and selection criteria, see additive manufacturing material.
See also our earlier report, Gas Alarm Controller Selection for Electrical Work: Channels, Outputs, and Compliance Map.