Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 100 MHz high-speed strain monitor using fiber Bragg grating and optical
  filter applied for magnetostriction measurements of cobaltite at magnetic
  fields beyond 100 T   High-speed 100 MHz strain monitor using fiber Bragg grating (FBG) and an
optical filter has been devised for the magnetostriction measurements under
ultrahigh magnetic fields. The longitudinal magnetostriction of LaCoO$_{3}$ has
been measured at room temperature, 115, 7 and 4.2 K up to the maximum magnetic
field of 150 T. The field-induced lattice elongations are observed, which are
attributed to the spin-state crossover from the low-spin ground state to
excited spin-states.

21
The categories of this paper are: adap-org
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
6
The categories of this paper are: astro-ph
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
16
The categories of this paper are: stat