Home > Techniques and equipment > Solid-state nuclear magnetic resonance

Solid-state nuclear magnetic resonance

Solid-state Nuclear Magnetic Resonance (NMR) provides information about the local chemical environment of an atom.

It is a well-suited tool for a better understanding of the structure of materials, whether crystallized or amorphous, in order to establish a link with their physico-chemical properties.

Where most characterization techniques focus on electrons, NMR focuses on nuclei. It consists in detecting variations in the magnetization of atomic nuclei when acted upon by a powerful magnetic field and an exciting electromagnetic wave.

Our solid-state NMR instruments

Bruker Avance III 500 MHz spectrometer

Bruker NEO 300 MHz spectrometer

Bruker Avance III 200 MHz spectrometer

To know the rates and have access to our solid-state NMR instruments, please contact us by email:

Member of the Fédération RMN Solide Hauts Champs (FR2950 CNRS)
National (CEA, Montpellier and Amiens universities) and international (Australia, Canada, Italy, UK and South Korea) academic collaborations.
Collaboration with Umicore to characterize surface impurities on electrode materials for lithium batteries (read the publication).

Examples and applications

The solid-state NMR equipment of the PLASSMAT platform has contributed to the characterization of numerous types of materials. Examples include materials for photovoltaic (¹¹⁹Sn, ⁶⁵Cu, ⁷Li, ⁶⁷Zn, ⁷⁷Se, ¹¹³Cd) and polymers (¹³C) and hybrid perovskites (²⁰⁷Pb,¹¹⁹Sn, ¹³C, ¹⁵N) and battery materials (⁷Li, ⁶Li, ¹⁹F, ³¹P, ¹³C, ²⁹Si), the clays (²⁹Si, ²⁷Al, ²³Na), hydraulic binders or geopolymers (²⁹Si, ²⁷Al, ²³Na) or glass or glass-ceramics (¹¹B, ²³Na, ¹⁷O, ²⁹Si, ²⁷Al,¹⁹F).

NMR allows to characterize poorly-crystalline or amorphous materials:

Left: ²⁹Si MAS NMR monitoring of the appearance of C-A-S-H cementitious phases over time during lime treatment of a calcium bentonite (read the publication);
Middle: determination of the B^III/B^IV ratio by MAS NMR of ¹¹Bin borosilicate nuclear glass (read the publication);
Right: MAS NMR monitoring of ²⁷Al during dehydroxylation of a clay at different calcination temperatures (see publication).

Using spectrometers with different fields is sometimes essential to unambiguously determine the interaction parameters of the sample. For example, nuclei such as those of copper or vanadium, may exhibit chemical shift anisotropy and a quadrupolar interaction of similar magnitude. Obtaining multi-field spectra is of great help in separating these interactions, which depend on the field in opposite ways.

On the right, you can see ⁶⁵CuNMR spectra of the Cu₂SnS₃ compound acquired under MAS or static (WURST excitation) conditions at 2 different magnetic fields. These different experimental conditions enabled us to unambiguously determine the 8 interaction parameters associated with each of the 2 crystallographic sites (N and W).

The selective nature of NMR (the response of each type of nucleus is acquired independently) can allow isolating the signature of nuclei present in small quantities in a material without being hindered by signals from other chemical elements.

NMR spectra (MAS and 3QMAS) of ²⁷Al in the crystalline compounds (In_1-xAl_x)S₃ were used to determine the different sites occupied by the aluminum atoms and quantify the occupancy rates depending on x.

NMR also provides information on the connectivity or spatial relationships between atoms in a material.

On the left, an INDEQUATE NMR spectrum of ¹¹⁹Sn showing the connectivities (through chemical bonds) between the different ¹¹⁹Sn sites in a stannate.

On the right, ²³Na-³¹PD-HMQC correlation spectrum showing the spatial proximities between the different ³¹P and ²³Na sites of the Ca_9.5Mg_0.5Na(PO₄)₇ compound.

NMR can be used to characterize materials for batteries, as can be seen from these 3 examples:

Right, ⁷Li MAS NMR spectra of lithiated species on the surface of LiNi_0.5Mn_0.5O₂ electrode material. Chemical shifts (~0 ppm) correspond with diamagnetic species whose broad rotational band envelopes demonstrate strong interaction with the underlying paramagnetic material. As the thickness of the surface deposit increases, the width of the signal decreases, indicating a decrease in the dipolar interaction between the paramagnetic centers of (LiNi_0.5Mn_0.5O₂) and the ⁷Li nuclei of the diamagnetic species.

The composition of the electrode/electrolyte interface has a major influence on battery performance. NMR quantification of lithiated and fluorinated species of ⁷Li and ¹⁹F for positive LiNi_0.5Mn_0.5 electrodes during electrochemical cycling in a LiPF₆-type electrolyte enables direct comparison of the quantities of lithium and fluorine involved in the electrolyte degradation products at the electrode/electrolyte interface.

The use of the MATPASS sequence, applied at low field (200 MHz), enables a detailed study of lithium environments within complex structures such as those of lamellar positive electrode materials like Li₂MnO₃ (left), NMC811 (right, 1D projection) or spinels. Opposite to the MAS spectrum of NMC811 ⁷Li(right, orange), the resolution using MATPASS (right, blue) ensures that there is no signal around 1300-1400 ppm, and therefore no lithium in the transition metal layers.